When it comes to understand what happens on the strategic map during your campaign there are some subtle things not written in the game manual. Let's go through them.
In many youtube videos the voice goes like this: "And now let's wait until something exciting happens and I will come back...". The video maker waits for an encounter to happen, this helps him to shorten the video but gives a totally false image of the game. The thing is: You don't have to wait for an Encounter to enter a battle with enemies.
Red icons from enemies on the map are a big help for you, not only for getting an encounter but for knowing in which direction the icon is moving before it fades out. Don't miss to put at least 2 markers (P key) to save its starting and second position to have a plotted route. And now let's point-out what really is important:

The tactical map has a diameter of 54 NM, so if you can get your forces within this range in the strategic map before going Tactical then they will appear on the battlefield together with enemy forces if present.
This also means You don't need any red icon to enter a battle, it's enough to be within 54 NM and having a good estimate about where the enemy is in that range.

A red icon will not stay forever on the map, it will move then fade-out before getting invisible. If it's a plane you must judge if it's part of another task force located somewhere. If you go Tactical at that presumed point of the task force you should make contact with it if your forces are close enough and have the means to detect it. In short: Do not wait for an icon to appear if you have good clues about where the enemy is. Go Tactical! The worst thing that can happen to you is that you need to retreat in front of overwhelming forces, but in this case you can at least identify them.

Tip:
It's very effective to launch Kingfisher scouting planes from your CA / CL in the strategic map before going Tactical, so you will cover all targets that are over-the-horizon and could not otherwise be detected by your task force.
Also when you have a CV, be sure to launch its planes for attack or defense BEFORE going Tactical, or BEFORE entering the 'Encounter', that's the only time you can do it, during battle it's too late, you can't do it!

The moment you go Tactical the strategic map is 'frozen', so it doesn't happen that your forces are moving on the strategic map while you are busy in the battlefield. It's therefore useless to send your forces towards an 'Encounter' point in the strategic map hoping that they will join you during battle, not going to happen. For any of your forces to spawn on the battlefield they must already be close to the encounter point, within 54 NM.
And what's adding chaos to this frozen strategic map is: The time is reset after a battle, how is this? This creates a lot of confusion to new players - also because not mentioned with a single word in the manual or tutorial, but this mechanic is quite logic and makes sense: See, you are not a pilot, not a ship or sub captain, you are a Fleet Admiral commanding naval operations in the Pacific and you are standing in front of a strategic map. You have to decide the action of ALL your forces on the map. And how could you possibly do this when spending real-time in a battle? Well, you can't in this game, unless...the time is rest after a battle, simple as that, good idea, isn't it? So what happens is that the time is reset, all unit positions have not changed, but all incuring damage to ships, planes, all losses, all rewarded points are accounted for. So you can handle other units on the map which otherwise you couldn't had the game not made a time reset.
In short, it's a mechanic that allows you to control pretty everything happening on the strategic map at the same time, even when entering a battle.

The special case of Submarines:
An exception to all this are enemy submarines. Currently, submarines are never shown on the strategic map but can theoretically be found by going Tactical if you do it at the right place. Oh my...So, without red icon, how would you find it, do you have a 6th sense? Well, you could try to find it after the sub has attacked your fleet with torpedos - and the Cooldown time of 4 hours is over (see more below about cooldown times), I wish you good luck, but anyway: that's too late chap, and the damage is already done...
In my chapters about submarines more below, I will give you the means to make subs visible on the map again to eliminate this odd gameplay.

Cooldown times
After an encounter, when retreating at the end of a battle, the game will start a cooldown timer where contact is lost with the enemy (the current game manual shipped with 1.08h5 is incorrect about the time, 60 minutes is wrong). It's useless to try to re-enter battle, you won't find the enemy. You must wait until this cooldown time is over in order to re-engage the enemy.

Tip:
You should not be afraid of the Cooldown Timer, but instead remember the initial heading taken by enemy forces. If you spot them you can place map markers on the strategic map later to search for these enemy forces again. Also take the time to identify all assets if you intend to retreat without being detected, this will save you a lot of time later when your TFs enter the scene! Don't forget: Identified targets give you a better firing solution (+10%) and makes it more likely to hit the target!

The exact cooldown times are different for the type of forces, and currently for the 1.08h5 version they are:
- 30 minutes for ships
- 15 minutes for planes
- 4 hours for submarines
If ever you feel the need for it, these numbers (in seconds) can be modified in the setup.txt for the appropriate campaign.

Whatever campaign you start, wether the vanilla campaign or a modded one, you must ask this crucial question and take the necessary steps:
You will have to invade a forward point, a neutral location or an enemy location without airfield or port, this with the purpose to give your planes a better range of action. You must ask what location will give your Avenger-type planes (which are multi-role planes) a good range for attack, defense and scouting. Air superiority is prime in a campaign. If your Avenger-type planes cover several enemy locations, the more so will your B17F heavy bombers later when you airfield is upgraded. Thus, forward points that meet these conditions are your absolute priority when you start a campaign. Try to build a level 2 airfield at such locations as soon as you can, this will increase your planes to include 4x Avengers, your campaign ongoing will be much easier and productive afterwards.
Only later in the campaign, after earning more Command Points, you can afford to introduce Aircraft Carriers and Battleships in your game which will greatly help and simplify your tactics and strategies, however read in my 'Basic game strategy, Part IV' what you must consider when playing with CVs.

In the vanilla campaign, you start with plenty of Supplies and Troops, but only very few Fuel and Engineering which also will be very hard to get during the campaign and you only start with those placed in your Homeport. Think very carefully about how you spend Engineering and Fuel because you cannot undo these decisions! Troops and Supplies can be moved from one port to another if they are urgently needed, but once you have used your fuel or engineering resources that's it, they are gone!

Never, never and never...leave your unloaded Engineering and Fuel in a location without immediately using them to upgrade your ports or airfields. If your location gets invaded by the enemy he'll say thank you and your resources disappear. This will take you weeks or longer to get resupplied with them in decent quantity.

Also when loading supplies at your homeport, always get your warships full of supplies and troops, not only your cargo ships and oilers. It doesn't matter where these warships are moving or what they do (wether escorts or ASW patrols or whatelse), at some point you can debark troops or supplies at some nearby location if needed and you will save travel time if you already have these goods onboard your vessels.

Upgrade your airfields, not your ports. You will need plane coverage to make a good campaign. The game will reward you with 3 CPs per port level, but those are peanuts compared to getting the necessary fuel and engineering, so forget it.
These are the only times I upgrade ports:

• If I really need to defend a location against enemy troops, every upgrade gives me +20% defense bonus

• If a port is very well placed to rearm ships (then I upgrade to level 3).

• If it's required for winning the campaign (In Watchtower operation you will need to build a level-5 port at Guadalcanal).

Other than that it's not worth upgrading ports, also because you must launch all your new created fleets from your homebase only.
This is true for the vanilla game, with major mods the strategy and opportunity to upgrade ports may be totally different.

Destroyers (DDs)
I can be short here: Chose the Porter Class, everything else being equal this unit has the largest nr. of guns: 8 of caliber 5 while other units have less than that.
Note: I have not checked it, but if you play without enemy submarines there is little point to play with any destroyers whose primary goal is to do ASW (Anti Submarine Warfare), instead invest in ships with good AA and gun firepower to defend your merchants and oilers.
In all cases and against enemy planes, make sure to chose a formation where all your ships are close together so that the AA will be most effective.

Light Cruisers (CLs)
They have triple the firepower of DDs but except the Atlanta class they don't have sonar and depth charges, but instead they carry 4 Kingfisher scouting planes. A light cruiser other than the Atlanta is the cheapest solution to get these planes and a good addition in artillery protection for your cargo ships and oilers.

Heavy Cruisers (CAs)
There are differences in the air and surface radar ranges. Chose the unit Class with the highest range, everything else being equal. CAs are necessary to bombard enemy locations, bigger Battleships (BBs) do it even better but those are not mandatory.

Submarines (SS)
The better speed, especially underwater, and its test depth should be your points for chosing the unit which should be the Gato Class when starting.

Battleships (BBs):
You should not chose any Battleships when starting, they are expensive and if you lose them your campaign will be over soon, not having enough 'points' to buy other assets and being effective.
Ideally, battleships should only attack their targets from far away not going close to the enemy which will greatly expose them to multiple attacks. For that reason they must be well-defended with escort ships also for the case of enemy air attacks. Always choose a CIRCULAR formation for your BB and escorting ships (your BB being in the center) in case of air attacks and never use any line-up formation that greatly puts at risk your BB being attacked individually without much AA resistance. The same holds true in case of submarine attacks, it's better to lose a DD instead of the BB being easily hit by multiple torpedos (the sort of thing you can hardly afford when starting, thus my advice not using BBs too early).

What BBs can do, strong and weak points:
Battleships have little value on sea when at close range in that they carry no torpedos and cannot otherwise assist other ships which is more the domain of DEs, CAs or CLs. the BBs firepower is substantial with multiple 16 caliber guns but nonetheless, they are quickly vulnerable from multiple attackers even by more simple destroyers which all cannot be attacked at once and which use fast-reloading cannons against the BB, so the BBs big caliber and slow-reloading weapons get quickly insignificant. The shining side of BBs is: They are prime when it comes to attack land targets (at least in this game), the damage sustained by land targets primarily depends on the amount and type of ammo fired and here, BBs have a big advantage. However don't overestimate their power: My tests are not concluded yet, but my take is: 1 BB has little advantage over 2 and more CAs in a land attack, wheras 2 BBs + CAs have a huge advantage in getting the levels of airfields and ports down quickly.

Aircraft Carriers (CVs):
You can play poker by chosing to buy a CV when starting (very expensive, will cost half of your total CP points) and put it in a position to make its planes attack most of the enemy locations and detected fleets. But I would not. The many available aircrafts look good but: Once most of the carrier planes are destroyed you will have to release the CV to get more planes for it, that's far from being a good deal. That's because planes die like mosquitoes in this game.
Ideally, you should never see your CV on the tactical map. If you get into an encounter with it then you've done something terribly wrong before! CVs cannot sustain any combat and are easy targets for submarines, torpedo or dive bombers, so they must avoid encounters at all costs, and this is done in the strategic map by good scouting, dedicated ASW patrols (which make no sense in vanilla currently because submarines are not shown on the map, so you would have to mod the game to make them visible when detected, see my submarine chapters) and submarine patrols protecting the CV route BEFORE it reaches this route. Problem is: At the start of a campaign you hardly have the ressources to do this effectively, although Kingfisher planes launched from CAs do a good job if you handle their waypoints intelligently, but they will not be enough to avoid your CV to get trapped by submarines or faster enemy interception fleets. That's why I recommend not chosing any CV when starting.

What CVs can do, strong and weak points:
My judgement is a kiss of death for these units, they should never have been used IMO, they have no stealth qualities, they are terribly exposed requiring a lot of defensive units that could all well be in action elsewhere, they only remember me of big battleships of WWI that quickly became obsolete in WWII and were not used anymore. Not so CVs that are even still being used today contrary to any good sense. Same goes with tanks by the way, but I digress...
So what can they do? Pretty nothing but being a moving airfield, that's not much compared to invading a good placed airfield in enemy territory which has much more value. And that's pretty it, everything else is weakness (only in this game of course) which quickly transforms the CV into a sitting duck when not having enough planes anymore or being damaged forcing it to move at low speed which is a death sentence.
In this game I have a hard time to find CVs very useful unless I apply some mods (see next chapter) , mainly because of the Release requirement to refill planes, my CV planes will all die at some point leaving me with a big unarmed ship that I need to take care of and I waste considerable time to get new planes for it. That's where I think I should have spent my points to buy other units!

Read my next chapter here below to know how you set your CVs to use the 'Rearm Ships' option to get their lost planes replaced which will greatly enhance your gameplay with them, turning them to be really useful assets.

The newest vanilla game version as well as the major mods of the game require you to release a CV in a level 5 port to get its lost planes replaced. And that takes time. 2x the distance to a level 5 port to get it back where it was + several days in release state at the port (at least 2 days if not damaged).
To my taste, the release requirement while being realistic considerably hampers the gameplay up to the point to make CVs useless assets due to the sheer overkill of planes in the game. The release option disabled instead makes a HUGE differene in time saved and gives your CV much more value - as it should be.

You can chose to disable that in the initial campaign options, by deactivating the box

New Carrier Aircraft require Release

After deactivating the box all you need to do to get new planes is to travel with your CV in a level 3+ port and chose the "Rearm Ships" option. But still the waste of time is not to be neglected (2x distance to the next level-3+ port), you may be in better shape by quickly upgrade a good-placed airfield to level 3-5. Or you have 2 CVs which you move dynamically to fill the gaps. Note that if airfields lose planes they are replaced the next day, that's a huge difference compared to CV planes.

In the case the above campaign option doesn't work or is not available edit the setup.txt file in the appropriate campaign folder (or at the same path in the overide folder in case of a mod) located in

C:\Program Files (x86)\Steam\steamapps\common\War on the Sea\WarOnTheSea_Data\StreamingAssets\default\campaign\[the campaign folder you want the change to apply]

In the setup.txt, replace

"carrierWingsRequireRelease":true
with
"carrierWingsRequireRelease":false

With such a modified setup.txt, expert players can easily create a JSGME mod to be applied in vanilla or as a submod in a existing mod.

Thank you jfoytek for sharing this info in the forums!

IMPORTANT:
The sonar settings in the Options menu that allow you to set 1x, 2x, 3x, 4x the sonar ranges for all units with sonar in the game, these settings are currently broken in 1.08h5. Only 1x sonar range will work whatever you set in the sonar options.

Before we enter the topics about submarines and anti-submarine warfare (ASW) we need to know how Sonar works and the reasons for why sonar detection ranges will get severly crippled up to making sonar detection impossible. A lot of complaints about overpowered submarines, about how hard it is to play with submarines or hunting them efficiently, all this has mainly to do with not understanding how the sonar mechanics work in this game. Sea state and weather is not everything, there are other finesses to know. The good news is: I will keep it very simple with only few things to remember, so you will be well prepared to use your submarines or ASW units at their best.

Only destroyers (DDs) and the light cruiser Atlanta class are equiped with sonar (in the vanilla game) because also equiped with depth charges to sink submarines. Sonars are devices placed under the keel so they are submerged to dectect objects that are also submerged. The sound propagation speed under water is 5x increased compared to sound over the water (in the atmosphere), that's why sonar isn't used on the surface above the water, it woudn't work.
Passive sonar is a listening method to detect sounds emmited by objects in the sea, whereas active sonar uses a sound wave (ping) through the water to be rebounced to the source when it reaches an object under water which can be a lot of things like plastic and other debris, fish swarms, plancton groups or... ship keels and submarines.

Sonar detection ranges:
Different ship models may have different sonar detection ranges. Watch the Ship Recognition Book to know if a ship is equiped with sonar and what the detection range for passive and active sonar for your particular ship is, keeping in mind that those numbers apply only for the most optimal weather and sea conditions without thermal layer and without surface duct. You will almost never meet these optimal conditions, meaning that your actual detection range with sonar will be much less in many situations. This is true for both the sonars of ASW units and submarines.

Question is now what exactly will reduce these numbers? It's very important to understand it or you will perform miserably in your game...
The factors that will reduce the sonar range are in order of importance:

• Speed of the sonar source (A ship with sonar going over 10 knots will not detect anything)

• Rain or storms (will cut the detection range by 50%)

• Target profile (a target pointing away from sonar source reduces detection range. Will only apply for active sonar)

• Sea State (the higher the sea state number, the more reduced is the detection range)

• Duct Strenght (only if a thermal layer is present. Depending on this number this can favor the ASW unit or the submarine if the sub stays above the layer)

• Layer Strenght (only if a thermal layer is present. Indicates how much the detection range is reduced for ASW units if a sub goes below the layer)

• Target speed (the lower the target speed, the harder sonar detection will be and vice-versa. Applies only for passive sonar and the effect in this game seems to be much weaker than it should)

What really is important to remember, wether you play with ASW units or with a sub, are the strenght numbers, namely the layer strenght and duct strenght, and this only matters if a thermal layer is present. Because these strenght numbers are multiplied with the normal sonar detection ranges, we have a simple rule to remember for all combat engagements:

Strenght numbers larger than 1 are bad for submarines and good for ASW units.
Strenght numbers below 1 are good for submarines and bad for ASW units.

Example 1:
Sea State: 2
Thermal Layer: Yes
Layer Strenght: 0.7
Duct Strenght: 1.4
This means a submarine will be 40% easier to detect by ASW units if it navigates above the layer (duct strenght), but it will be 30% harder to detect if below the layer (layer strenght), however the sub will equally have a 30% reduced range to detect ships while under the layer and a 40% better range when above the layer (however this is rather irrelevant when escaping). The low sea state number will not significantly decrease the detection range which means it will not compensate for the duct strenght and thus: Staying above the layer is dangerous for the sub, when escaping it should go below the layer as soon as possible.

Example 2:
Sea State: 6
Thermal Layer: Yes
Layer Strenght: 0.61
Duct Strenght: 0.71
Such a situation is very good for a submarine to escape and very bad for ASW units to detect the sub because of the combined numbers of high sea state and very good duct and layer strenght for the sub. Note that the penalities in detection range are cumulative for ASW units in this situation, making it very unlikely to detect the sub at all.

Example 3:
Sea State: 3
Thermal Layer: Yes
Layer Strenght: 0.98
Duct Strenght: 3.5
You can see here that a submarine is in bad shape wether above or below the layer and the moderate sea state doesn't really compensate for the sub's other bad numbers. Notably it's the duct strenght which is very bad for the sub here and therefore very good for ASW units giving them a whoopy +250% detection range bonus when the sub navigates above the layer. The layer is also not strong, not giving the submarine much of a safety margin.
In such a situation when playing with a sub, I would only consider to attack the most valuable targets and leave everything else alone due to the high risk of being detected and relentlessly attacked.

Example 4:
Sea State: 6
Thermal Layer: No
Time: 01:34 (night)
Weather: Stormy with rain
This is arguably the best possible situation for a submarine and the worst one for ASW units to detect submarines. The sub can easily evade on the surface without being spotted as long as it maintains a low profile (pointing away from the ASWs) while reasonably far away (2 kyds or more), and even if it has to dive it would be safe making any sonar detection from the ASWs close to impossible because of the combined penalties of high sea state and rain.
Note that when playing with the submarine you will have a very hard time to identify the targets and it will take much more time to get a good firing solution for your torpedos.

Tip:
The presence of thermal layers and the related strenght numbers are randomly set when entering the tactical map but the weather and sea state are not random and can be displayed on the strategic map. It's well worth to frequently enter Tactical on the battlefield with your submarines with low sea state and good weather to see if there is a good Duct Strenght for you. If so you can often considerably increase your sonar detection range and detect enemy units that otherwise you wouldn't detect so far away.

I will discuss in details the differences between passive and active sonar in the chapter "How to defeat enemy submarines".

Submarine warfare is the most controversial and complained game mechanic in WOTS. I will go into many details in this and the following 4 chapters because of its significance during campaign play. Many new starting players have problems with submarines mainly because they misunderstand or ignore the sonar detection ranges (see last chapter). Some players think that submarines play a too large role in this game. They do, and for a good reason:
According to Naval historian Gary E. Weir, “In all, U.S. submarines destroyed 1,314 enemy warships in the Pacific, representing 55% of all Axis power warships lost and a total of 5.3 million tons of shipping.”
Submarines are an important asset in this game, and yes, the enemy side (call it AI) spawns them all over the place, but unfortunately, the game doesn't play too well with them to give you a satisfying challenge and custom rules and fixes are necessary, I will speak about this in the following chapters. For now, just know that you can switch all AI subs to OFF in the campaign options if really you can't stand them.

IMPORTANT:
The sonar settings in the Options menu that allow you to set 1x, 2x, 3x, 4x the sonar ranges for all units with sonar in the game, these settings are currently broken in 1.08h5. Only 1x sonar range will work whatever you set in the sonar options.

Tips when using your own submarines:
It's a bad idea to directly put submarines in your fleet together with CAs, CLs, DDs, they will only slow down the entire fleet. Buy single units of them and send them on patrol, like it was done in the real war.
Let's say your planes have spotted a big enemy fleet with about 10 ships including at least a BB or CV. It's very tempting to now immediately send a group of 10-20 bombers to attack that fleet. But what you should do is: Take a second look on the map and see if one of your subs is nearby and send it towards the presumed encounter point, and only then send your group of planes so that they arrive in timely manner together with your submarine. Oh, you have more than 1 sub nearby? Welcome to the party...And of course, in the meantime you can as well send groups of planes to bomb this target so to 'soften' it and make things easier for your second attack wave.
You must realize that submarines perform much better and do much more damage to enemy ships per weapon used compared to any other warship or plane, stealth really pays-off and they are prime to support your warships on the field too, for example a torpedo attack will throw enemy ships off-course taking a route where they can be slaughtered by your surface warships. To execute this correctly, you don't need to 'Merge' your sub with your fleet but only get it within 54 NM close the point where you go Tactical together with your fleet or your planes.
Afterall, submarines do a cheap combat for you. That sounds heartless and disgusting, but fact is: A sub costs only 10 command points and losing one is not a big deal. And who says that your sub cannot escape? It CAN if you play well, it's up to you, and in the example here there are still your attacking planes to disrupt any effective pursuit of your sub.

Attacking with subs on the battlefield:
You should attack oilers and merchants before any other ship, their loss will at best help your war effort, in that regard these assets have almost the same value than a battleship.
Once you have fired your salvo of torpedos you must hit the road asap. If you plan to get in a new position to fire another salvo then you must stay at periscope depth and make an educated guess about which course the ships will follow after your torpedos have exploded. You want to take a course in parallel to the estimated course taken by the remaining merchants, oilers or other targets of value after the hits of your first salvo. And now, these escaping ships will be moving at maximum speed, so you have to judge in advance wether your firing parameters will still be good.
Should you make a second salvo? YES If there is a strong thermal layer or a favorable duct strenght for you. If it's night with rough sea then MAYBE because you'll have a good chance to escape on the surface if still you are more than 2 kyds away after the 2nd salvo. Your 2nd salvo must be fired once you know the new course of the escaping ships or it will most certainly miss!

In other situations, at daylight, without thermal layer etc. I would care about making a good escape immediately after firing my first salvo by taking a route that gets me away as fast as possible, not going deep immediately but staying at periscope depth observing the enemy so to know the optimal heading for escaping (when far away enough, escaping on the surface at night or during a storm is of course the better choice). I know I will get a new chance to attack the group in another battle after the 30 minutes cooldown time is over!
Then, I also have to judge wether to attack the target at all. If a high valuable target was previously located on the strategic map then I will leave this target alone if it doesn't have oilers, merchants or battleships in it and if the escape conditions are difficult, that would be a bad risk-reward situation.

Your sub has a deck gun but in this game (when playing vanilla) it's rather useless in that 1 single cannon hit even from a damaged merchant will sink your sub. Therefore, forget about using your deck gun, it only gives away your position and you'll soon get killed by a lucky enemy shot. Also if your sub is submerged and you want to get away from the enemy at the surface, be sure you have 'Fire at will' disabled or your deck gun will cheerfully start to fire if in range of any enemy!
In some game mods I expect enemy merchants and oilers to be unarmed most of the time, so my deck gun will be more useful to 'finish' a damaged target, if other armed ships are further away I would then fire some shots and dive to avoid fatal hits on my sub, then surface elsewhere and repeat. Wether this is a good idea I'll have to find out...

Tip:
You can dive with your sub very fast if you counter-flood one of the 'General' compartments, you will start to dive and sink, but then you must immediately send a repair crew to the flooded compartment to stabilize your sub again.

Important notes:

• Have a firing solution for your target close to 90%
  Don't even bother to fire torpedos if your torpedo solution is far below 90%. Correctly identifying the target or waiting until the game does it for you, this will at least give you 10% more solution points.

• During my play I found that If I wanted to set a new target for my torpedos, I needed to first reset the Directors in the torpedo UI by hitting the 'Stop' button and only then chose a new target with T, I have seen that not doing this will cause my torpedos to completly go in the wrong direction and miss the target!

• I have this confrimed from the devs in a forum reply: To detect targets so they appear on the map, you need to actually look thought the periscope, not just raise the scope. And for this to work the observed target must be within visual range of your unit which is 4 NM for submarines, you may see targets further away through the scope but those targets cannot be detected until you get close enough and therefore will not appear on the map. They can however be detected by sonar and then appear on the map.

If you play with subs, always note the Thermal Layer (yes or no) in the menu tab. If there is a layer you will have a big advantage during escape after launching your torpedos, and you can even think about getting in position for a second major salvo. But don't overestimate the layer advantage: Active Sonar can still detect you if enemies get really close to you - at whatever depth you are. (Normally without layer they will detect you at 1NM away when using active sonar, but your secure margin with the layer is then only very slim...)

You must be aware that any warship that can go up to 30 knots will have a relative speed of 21 knots or more towards you if you are submerged, and once your torpedos explode they know in which direction to chase you by looking backwards at your torpedo heading, so if you stupidly didn't move in the meantime they will come directly towards you...and guess how fast they will catch-up...Manage to be at least out of active sonar range once they get close and start circling. That's why you generally can't afford to make a 2nd salvo with your torps unless you are far away with your 1st salvo.

Against planes:
If it's too late for you to dive (you need more than 60 seconds) go to flank speed which is 20 knots with a Gato Class and change your heading to present your entire broadside to the incomming plane to dodge at best any gun fire or bombs (you want the plane to be at +/- 90° relative bearing). After diving and the plane didn't release its payload yet be sure to change your heading so to disrupt his aiming, at calm see and good weather you need to go deeper than 100 feet to be sure not being visually spotted. If enemy ships are on the map even far away they know where you are at this point, so stay at high alert.

A little before enemy ships drop depth charges at you, increase your speed to maximum (9 knots) and make a hard turn for more than +/- 90° to disrupt their detection, they will lose contact with you for the next 20-30 seconds because of the minimum range of the active sonar, but be sure to be again at low speed and silent running after changing course. It's a difficult situation for you because depth charges don't need to hit you in full to make damage, it's enough when they explode nearby and that's why you should increase your speed to maximum to get past these exploding charges.
Be sure to check your damage status and prioritize flooding repairs.

Stay at periscope depth as long as you can, it makes no sense getting deep asap and losing all initiative and battle options. Being able to use your scope means you'll know where the enemy is and you can take the optimal escape route - which is one directly pointing away from them which gives them the lowest sonar profile.

Active sonars from ASW units will detect you 1 NM away and if they have a favorable duct strenght this range can be sensibly increased (read my chapter about Sonar Detection Ranges). So DON'T get into that situation, plain and simple. Wether deep or at persicope depth, it doesn't matter, you will be detected.

At some point it's better to kill a destroyer to make a better escape. When firing a spread of torps from the rear tube, even if they all miss you have forced the enemy to turn away from you to avoid the hit - or you land a kill. However, if too close your torpedo will not explode when hitting the target, be at least > 0.5 kyds away when firing.

Some skippers had the idea to be very close before launching their torpedo salvo and hide just below a moving merchant at the same speed, or to stay near a crackling wreckage which disturbs enemy sonar, but frankly, I don't think this will work in the game...If you try this then be sure to enable Ship Collisions in the game options or you won't have any advantage with this tactic.

Your sub can take 1 flooding damage which will cause you to sink and needs to be repaired immediately, a second flooding will force you to use the 'Emergency Blow' button to get you surfaced - without any chance to dive again during this battle, this unless the sea floor is above your critical depth or if your crew is able to repair both floodings before you sink to the point to implode (which I have never managed). You only have 1 repair crew, so you cannot repair 2 floodings at the same time. Using the blow button will be hopeless for your sub in almost all cases, so do your best to avoid this scenario.
If you get in this desperate situation having 2 floodings you still have a few options to survive. Before and after hitting the Blow Button try by any means to make the enemy lose your track, you can venture to go as deep as 1.5x-1.75x the test depth before hitting the button and hope that once surfaced the enemy has lost contact with you. If that's the case, at night and with rough sea you'll have a chance to evade on the surface, get away at SLOW speed with your lowest profile pointed away from the nearest enemy, don't make too large water wakes at higher speeds that will make you visible...Of course this will not always work but those are your best odds, if the enemy already knows where you are when you surface then you are doomed, fire all your torps to get a lucky hit, go flank speed and zig-zag away, for me that has never worked well.

[WORK IN PROGRESS]

Your cargo ships should always be escorted by at least 1 or more warships equiped with depth charges to fight attacking submarines which is by far the major threat in this game. Planes make 1 run and must leave the scene because short of bombs but submarines can still be nasty with multiple attacks - if not in this battle then in the next one if you miss to sink them.

What follows are tactical tips to play with your destroyers and light cruisers to find and defeat enemy submarines (heavy cruisers and battleships don't have either sonar nor depth charges and should leave the scene quickly). I show that your chances are slim with only 1 unit, better with 2 units and almost a secure win with 3 or more chasing units assumed you are reasonably close to the enemy's submarine position.

Before I start discussing the different maneuvres with 1, 2 or 3 destroyers, we need to be aware of some important sonar facts that will also dictate some of our basic tactics:

• Passive sonar will work best with calm sea up to Sea State 4; above that the sonar range mentioned in the Recognition Book will start to get severly reduced.

• Rain or storm will reduce all sonar detection ranges by 50% (additionally to sea state penalties).

• With whatever sea state, if your destroyer goes above 10 knots he has only very little chances to detect the enemy sub with passive or active sonar, and certainly not at the distance seen in the recognition book. The lower your speed below 10 knots, the better it is to detect an enemy sub with passive sonar, but even then, as explained above, bad weather and rough sea conditions can make any detection quite impossible.

• Once you make a contact with passvie sonar, be aware that it will again disappear very soon. The first thing to do is to remember the sub's heading and lead your different units in that general direction, you know that the enemy sub will take a long time to radically change direction. Navigate your destroyer so that it points to the full braodside of the sub while moving in active sonar range which is a range within 2 kyds to the sub (1 NM). Then reduce your speed to 2-4 knots If within this range and swtich your active sonar ON. You should detect it now but once the sub presents a lower profile, pointing away from your destroyer, this will make you lose contact very soon, so your destroyer needs to increase to high speed for a while, circling a little away and overtaking the sub then circling back towards the presumed sub position at low speed again to detect a better profile of it. At that stage be sure to keep a low speed or you will not detect the sub again, maintain contact running at low speed for as long as you can and let other units make the attack run allowing them to select the enemy sub as a target (T key). In short, always keep your spotting destroyer at low speed in a position to detect the sub at its best profile for you which is a +/- 90° relative bearing seen from the sub while your destroyer points at it (a T-shape), this will maintain contact for as long as possible.

• Consider a certain angle (I count 20-30 degrees left and right from the rear of my destroyer) to be the baffles, a dead zone where you cannot detect a target by sonar, no matter how close it is. The good news is: All this is also true for the enemy sub, a reason why you should not have constantly your active sonar on to give your position away unless you want to maintain contact within 2 kyds!

• Active Sonar gives a detection up to 1 NM which is 2 kyds, but it has a dead zone within a minimum range where you will lose contact with the enemy sub (or not detect it at all), for example, if you navigate just over the sub you won't have any contact because of this minimum range. So, within these 2 kyds you actually have a very limited time to detect the enemy sub while it navigates outside of this minimal range and not beyond 2 kyds. Instead of making a detection in the first place, by using your active sonar you essentially hope to maintain contact with the target which is important to make auto-attacks possible by selecting the target with the T key. If your active sonar detects the enemy sub be sure to drop your speed to match the target speed. Maintain contact and let other units (if you have more of them) make the attack run.

Unfortunately it's not possible to place a map marker in the Tactical Map, only on the Strategic Map.
This would be useful for different reasons, for example to calculate manual torpedo firing solutions, or more obviously: To mark a presumed position of an enemy submarine after you have spotted torpedos on the map. Adding more markers would allow you to mark a circle in which the enemy sub could possibly stay when moving away at max speed from the marker point, and then you can make your ASW units move accordingly to cover at best this circle to start hunting effectively.

While there is no mod whatsoever to place markers, there is a workaround you can use to place a marker: I call it the Last Waypoint Trick, and that's how it works:

You will most likely have ships that will escape from the scene after a torpedo attack. Set a long escape route for these ships with waypoints but make it so that the last waypoint returns to the position you want to mark, and that's it, you have 1 marker that you can display by selecting the ship.
A second marker placed with that method by adding another waypoint with that escaping ship will give you a circle radius to work with, in the case of enemy submarines, if you place 2 markers with this method it will show you the maximum distance a sub can travel with 9 knots before your ASW units come in detection range moving towards the first marker. With a maximum speed of 30 knots for your ASW units, count 1/3 of the distance from your ASW ship position to the 1st marker, and then place the 2nd marker at this distance away from the 1st one, this will give you the maximum travel radius the enemy sub can do at 9 knots (rounded down a bit so you will arrive early) assumed that your ASW units will travel at 30 knots towards the first marker or to different edges of the circle, you can then start to search the sub within that circle at low speed and with active sonar at regular intervalls. You should then soon be able to detect the sub. Of course such a maneuver is easier to do with 3 ASW units, more difficult with 2 but still possible with only 1, although in that case you need to be lucky to detect the sub by guessing its escape course right.

A bit complicated, but it works well, and it's much easier to do it than to write all this down! I hope I make the detection of enemy subs with this method easier for you!

Some players find submarines are overpowered but I don't agree with that. If you are aware of the diffrent sonar factors that I have explained in the chapter above (sonar detection ranges) you will certainly have an advantage over AI subs which act rather stupidly sometimes, everything else than overpowered... And otherwise AI subs do the same job you do, nothing special with that.
However, some players get really bored that they get mainly attacked by submarines and nothing else while unable to spot them on the campaign map and they would like to remove them altogether from the game. You can do so (but before you do maybe read my next chapter):

Open default/campaign/campaignXXX/seaUnits.txt
Remove all lines that are submarines.

{"nation":"usa","available":[3,6,1940],"unitID":"tambor","cost":10}
{"nation":"usa","available":[31,12,1941],"unitID":"gato","cost":10}
{"nation":"japan","available":[30,9,1940],"unitID":"type_b1","cost":12}
{"nation":"japan","available":[10,11,1940],"unitID":"type_b2","cost":12}

You now have a vanilla campaign with no submarines.

An alternative is: You can disable the enemy using submarines in the campaign options before you start and never or rarely buy submarines yourself. Do so if you really believe AI subs are overpowered and you cannot defeat them or if you like to do without them.
To my taste, I get as many subs as I can, they will serve me well, for example in situations I've described in the previous chapter, or even for scouting purposes, and especially for protecting my own fleet by patrolling the areas on the map that my fleet will cross so to make it 'clear'.

Next comes the real controversial question, wether you should make enemy subs visible on the strategic map which you can do by changing the game files. But I will discuss this in the next chapter here below.

Due to inbalanced gameplay, the devs have made it so in the newest game versions (at the time of this writing it's the 1.08h5) that submarines cannot be detected on the campaign map. This is a provisory measure until they find a better way to implement AI sub and ASW techniques in the game.
Some experienced players find this a good solution, but I definitly find it's not, at least if you apply some personal custom rules regarding the handling of your submarines.

Here are the arguments in favor of hiding subs in the strategic map, I will quote but I won't give the names of these players having these arguments because I don't want this guide to transform into a personal debate, but please give these players the benefit of doubt because they are, as said, experienced.

- Player sub vs AI planes engagement. Completely broken mechanic. You as the sub captain press dive and wait for the timer to let you retreat from the battle. There is no danger only time wasted.

- AI sub vs planes. The player will always spot the sub first and the sub will only try to dive when they spot the planes ( around 4km ). So is completely unfair to the AI.

- AI will always send the planes to attack the nearest target in the campaign map. With subs , the player can use them as bait to make their fleets sail without any danger from air attacks. This makes the campaign to easy since the Ai doens't understand how to choose what target to attack.

Point 2 ignores the fact that spotting enemy subs (which then appear on the map as it should be) is not a 100% sure event, we just don't see on the strategic map everytime it fails, namely everytime a sub may be dived (because spotting you first!) or not spotted because of various reasons, also bad weather and high sea state, and anyway, a visually detected sub by an armed plane is a half-dead sub and rare enough to be allowed in the game, there is nothing unfair to the AI. The scenario where an enemy sub detects your plane and successfully dives and escapes, this is never played by you in the game, it already has happened in the strategic map without you seeing it, what remains in the tactical encounter are unfortunate enemy subs that didn't make it in time to dive and escape. So there is nothing unfair and still you must defeat the enemy sub, which from my play I cannot confirm that this will be an easy take-away everytime.

Point 1 is ridiculous unless I miss something: The job of submarines was to dive to escape planes, this happened in the war and that's what you do in this game (or you die), so what should I complain about? The AI will not make abuse with the Retreat button, so don't do it yourself.

Only the 3rd point is the real problem and all I can say is: Don't exploit it. Only the devs or some good mods could change it.

My case for showing subs on the strategic map - once you have spotted them - is:

• A more convincing gameplay; ASW patrols, planes and ships hunting for submarines, were an important factor in the Pacific war. Never showing any subs on the map is just throwing all ASW patrols away while you will suddenly spot a group of 6 torpedos heading towards your fleet with few seconds only to react, sorry but: these 2 events coupled that's not convincing at all, you may argue what you want, in short, if you throw out ASW patrols you also need to throw out submarines from the game. A better solution is to make AI submarines detectable and stronger instead.

• better protection for your fleets because seeing spotted enemy subs on the map will allow you to take steps against them, although, mind you, no guarantee that you will succeed, and to spot these subs you will have to send Scout planes like in the real war. And now, the story about the 6 torpedos suddenly comming towards your fleet is convincing: You have got your chance to detect and kill the enemy sub before, if you have failed then don't blame the AI for causing you to be in big trouble later!

How to revert to make subs visible on the strategic map:
Open config.txt and change:
"hideStrategicMapSubs":true to "hideStrategicMapSubs":false
That will revert the bahaviour back to how it was.

If you make the subs visible, you should follow some custom-made rules to make the game fair for both AI side and your side in the game like:

• Play with the subs visible on the map (by changing the config.txt entry),

• Set 1x only the sonar range in the game options to make it somewhat easier to evade destroyers with your subs at the price to make it harder to detect enemy fleets with them,

• In the config.txt file, set the enemy sub to have increased ambush numbers, this will give the AI sub better chances to escape after firing its torpedos and also gives the player more time to evade torpedo hits while keeping it still difficult to do so.
  "playerSubAmbushOffset":[3000,5000,1500,3000],
  "enemySubAmbushOffset":[1500,2500,750,1500] >> Change this into [2250,3750,1250,2250]

• (If you feel that you detect too many submarines on the campaign map): Raise the Cooldown Time for submarines from 4 hours to 12 hours (see under Cooldown times in the first chapter about the tactical map for how to do it)

• You may not takeoff planes armed with depth charges before detecting an enemy sub on the strategic map, but you can create ASW ship groups to patrol the map.
  If your planes detect an enemy sub on the strategic map (red icon): Select Ignore if you get an Encounter, don't go Tactical. Observe the red icon on the map, Set map markers to plot the sub's course. If you have a ship group within 200 NM which has at least 2 ships with sonar and depth charges (mostly DDs) you must split these ships out of the group to go hunting the sub at its presumed position if this can be done in a reasonable time (the sub may not head away from your ASW group in which case it would be almost impossible to intercept the sub). If instead your closest ship groups are further away than 200 NM then or you ignore the sub entirely or you throw a dice wether to takeoff planes armed with ASW weapons to attack the sub.

• If with a group of your ships you enter a forced Encounter given by the game and you see no enemy planes or ships on the battlefield then you may only change your fleet heading once a submarine is spotted or you have detected torpedos on the map. At night however, even if you see enemy torpedos on the map you must wait until they are less than 500 yards from your closest ship in order to start making course changes with your ships (these 500 yards actually give your bridge watchers magic eyes to spot these torpedos, but I guess it would be too much of a punishment asking you to do nothing at night until one of your ships gets a torpedo hit...which reflects the real war!). In absence of any such detection you may not change the heading of any of your ships, you are not supposed to know the presence of an enemy sub until it has been detected!

• When playing with your submarine(s) in Tactical, you shall not use the Retreat button until you are >8 kyds away from the nearest surface enemy and all enemies are heading away from you. Also no Retreat button while submerged.

• Only fight against enemy subs and use active sonar after detecting subs or their torpedos. An exception to this rule is for a group that only consists of ASW units.

With these custom rules you will give an advantage to the AI subs who otherwise will perform poorly or will be too easy to detect, and so hopefully make the game more balanced and challenging.

Fire At Will is a useful feature in many situations but NOT when it's activated for all units when you start a battle which is the default setting. There are several reasons for this, one is it gives away your position when you want this not to happen.

From KFG:

C:\Steam\steamapps\common\War on the Sea\WarOnTheSea_Data\StreamingAssets\default\config.txt

Change:
"autoGunneryDefaultOn":true
to
"autoGunneryDefaultOn":false

In the vanilla game the Rules tab will give the info about which and how many planes you will have if you upgrade your airfields to a certain level. If you play with some major mod (like Atlantic mod, TTE, Pacific mod etc.) then this info is not given. You can find the info at

MapandLocationstxt within the game or mod folder, this will list the planes you get at a certain level.

1) Create and launch the bombing flight, but DON'T give them any waypoints for now.
This will make them stay in range of the airfield.

2) After the Cooldown, launch the fighter escort flight and chose 'Escort / Fly over' option to make them join the bombing flight.

The range between 2 or more plane groups to use the 'Escort / Fly over' option must be not more than 11 NM.

Because you are at 0 time compression when seting up your stuff, planes will actually only takeoff once you release TC. If you have launched planes by mistake, simply order them RTB and nothing happened.

It's in the ...\Units\Sea folder, chose the ship and it's in the 'cargo' entry of the xxxData file. Damn...Should be in the recon book really...

Fortunately, in all major mods this info is included in a convenient table or in the recon book with

Tr: ...
Sup: ...
Eng: ...

(Fuel is only carried by oilers which will give the number only.)

For the vanilla game I list here the data for the ships you will use in the Watchtower campaign (USA side) starting with the most common ones. Note that every asset can only transport 1 TYPE of cargo, not several different types.


Ship type, Troops, Supplies, Engineering, Fuel

Atlanta, 250,400,0,0
Bagley, 250,400,0,0
Brooklyn, 250,400,0,0
C3 cargo, 1250,2000,100,0
Cimarron, 0,0,0,100
Gato (sub), 60,100,0,0
Northampton, 0,0,0,0
Porter, 250,400,0,0
Tambor (sub), 60,100,0,0
Wichita, 0,0,0,0

How you can detect all enemy units on campaign map:

Try this method. Open savegame file. Find and replace:
"spottedTimer\":0.0,
"spottedTimer\":5400.0,

Thank you Iv. for sharing this in the forums.

Tip: This will spoil the game for you if you use it too often, so restrain yourself please...
Use this only in very hard situations where you REALLY want to know the whereabout of certain units and don't try to 'memorize' all enemy positions, this only ruins your campaign experience, you have been warned!