Also, submarines are one of the few units that actually have a rudimentary AI enabled on them. I should probably rework this to have her spawn reasonably nearby but a bit farther away from the trawler/gunboat rendezvous.

The passive sensors in that area are pretty good and both the knox and foxtrot are remarkably easy to pick up via convergence zones in the area. They're both quite loud. My next task with this mission is to make some triggers for progressively declining weather... maybe a tropical storm blowing through or something... a worsened sea state might help masquerade both the sub and knox's passive signatures a bit better.

I'm not sure how far away a ship needs to be from a hostile submarine before she decides to prosecute it.

The knock? Explain, I am curious.
The triggers at present in the game are not capable of detecting flight-deck units. The helicopter is effectively invisible to triggers for the time being. The territorial waters are currently set for 15nmi from the cuban coastline along most of the coastline where the action would be taking place. I suppose I could consider dropping it to 12.

By the way, I had the knock set for 12 nautical miles so I could stay away from the Cuban coast. I was nowhere near it. My helicopter might have been.

When the trawler started heading north west again after meeting with the Zuck which headed south, my helicopter continue to follow them and my Knox continued to close to get to gun range in case I was ordered to stop it. That’s when the foxtrot sub very close to the trawler, launch three wake homing torpedoes on me. I was far enough away to head south at flank speed, and avoid them, but my help which have been hovering just behind, spotted the submarine and I gave it weapons free and it fired both mark 46s

I've tried to work around this a little bit, though I'm sure it's not bullet proof yet. Eventually you will be ordered to fire on the submarine via an intel message which should swap the triggers to a mission victory state for sinking the foxtrot.

There are more objectives to complete prior to sinking the sub [or even detecting it for that matter] including a search and rescue op.

In most cases that submarine is in Cuban territorial waters. I haven't drawn the "hitbox" for that territory because all you can make are circles right now and it's just a mess of overlapping circles... though perhaps I should re-evaluate this position and just deal with a bit of ugliness for the time being.

So, sight unseen ... and assuming nothing triggered incorrectly the Foxtrot would have been defending Cuban waters from 'Yankee Imperialist Aggression" or... whatever.

Thank you for the feedback, I appreciate it.

A lot of fun and learning experience. I identified all of the merchants, got a completed on the trailing the trawler and the Cuban Zuck. However, I was fired on by the foxtrot submarine with wake homing torpedoes against the Knox class frigate. To me that was an act of aggression so my helicopter destroyed it with two mark 46s and the game ended and I was defeated. Was I supposed to just ignore that attack and not attack back?