i think a aircraft carrier would be good
and maybe aswell as a destroyer AND OHHH the avengers aircraft carrier that would be a good advantage to your ais for this one

Maybe a WWII german torpedo vessel?

got a couple:
A landing ship (eg: the US whidbey island class)
A cruiser of sorts
and A PT boat with torpedos

Some interesting suggestions folks but don't forget to read the FAQ, especially the part regarding submarines and torpedoes, as well as a gentle reminder that any suggestions must fit in with all the others in this addon and already exist on the workshop (I'll reword that slightly to make that part a little clearer).

Huge creations like battleships and carriers aren't really recommended for Stormworks either as they slow the game down horribly for people who're not using a NASA computer and cause tons of lag in multiplayer, which makes it a miserable experience for anyone else that's playing on the server with you.

An alternative with pirates, using only small boats, could be very fun, and performance friendly as well.

Agreed. I even spoke about that as a potential mission in my video from last year, where the player (or players, if they bring friends along) could be tasked with intercepting pirates as they attack a tanker or cargo ship.

At the moment it would just have to be lone pirates roaming around because if the enemy ships spawn too close to each other they'd just end up fighting, as sadly the current version of this addon doesn't have gunner AI or factions/sides implemented yet... Maybe in the future though!

Add like a mini sub or like haflway sub with trops

Okay, I've just added some more detail taken from the FAQ and pasted it into the body of the text above to emphasise what kind of suggestions I'm looking for and why submarines, torpedoes and aircraft are not a good idea at the moment, as it appears as though a lot of people were getting a little too excited and skipping over that part. ;)

heavy reaper aircraft spawner

Originally posted by Robertson:

At the moment it would just have to be lone pirates roaming around

Well its exactly what i expected from this, lone and rare encounters during normal SAR missions. For me this is the best option for Stormworks.

Maybe The Type 2 Frigate?

Originally posted by ieatdonutsfordinnerrr:

Maybe The Type 2 Frigate?

nah that gonna be too op and laggy, cuz it even has good sam system

Originally posted by Killman88:

An alternative with pirates, using only small boats, could be very fun, and performance friendly as well.

This will be implemented soon

Originally posted by Professor Sins:

Originally posted by Killman88:

An alternative with pirates, using only small boats, could be very fun, and performance friendly as well.

This will be implemented soon

Nice!

Originally posted by smashleysav:

i think a aircraft carrier would be good
and maybe aswell as a destroyer AND OHHH the avengers aircraft carrier that would be a good advantage to your ais for this one

well i spoke to robertson on those. a destroyer and carrier would cause way too many issues. not to mention the lines of code wed have to make. plus the craft. and as he puts it: "where would the aircraft go upon the parent vessel being destroyed" not to mention the lag for said things