[2022] What's wrong with Co-Op nowadays

They exist in our game and are thus available in the matchmaking system. There is a side benefit of AI Submarines providing an experience where pings can be experienced and ASW can be used. Submarines do not dive lower than periscope depth, so it's not hard to shoot them when they give their position away through constant pinging.

I did relay this internally and the response is that the matchmaker allows up to two Submarines for players. We do not seem to have a way to limit the AI fill rates independent of potential human fill rates, so the up to 2 Submarine slots is there for use at the matchmaker's discretion.

They don't need to surface. The submarines repeatedly ping which tells you where they are. You can shoot the water a little to find the exact spot and then kill them through gunfire as normal.