I have found a mod that claims to add sharks to SH4. I have this mod downloaded but have never tried it, so obviously, I don't know if it does or doesn't work. Here is the download link over at SubSim.
Now I understand everything.
there is a server in SH-4 with mod sharks. In GWX 3.0 gold are dolphins in the game .
but if you do download the sharkmod to see them, that is something else
subsim has many hidden links. thanks anyway
I edited the 1.0 version to 1.1 with the permission from JoTheising, and in that process I tried to write some Shark traffic to the campaign. You won't see it unless that traffic is added to the campaign files. That is theoretically. Because I have simply not had the time to play for months, so I have just not got it fully tested. I'm not even sure if I added the traffic in the 1.1 version...