The mod also has it to where your submarine is visible beneath the surface, sometimes down to 120 feet, if the sea is calm and smooth. I have done extensive tests (previously - v76??) with calm, medium and rough seas. They do have to fly relatively close to your location, though that's kind of hard to determine. Depending upon the angle of the over-flight, they might see my boat with smooth seas, and the airplane would drop bombs, with my boat at 110-120 feet, though they usually were not close to hitting me. Come up to about the 80-90 level though, and they were quite close. At PD, they would get me about 1/2 the time. Make those seas "medium", and they wouldn't see me at 110-120, and at the 80-90 level they would seldom get me, while being at PD, they would get the boat about 1/4 of the time. Rough seas, and they usually didn't see my boat at all, even at PD, but they did occasionally and then drop bombs. I did have the benefit of "recording" (Save with Replay) the scenario, and going back reviewing from multiple angles (if desired), and at times, it was rather comical to see the airplanes twist and dive to drop their bombs, only not able to fully recover, "stall" and then crash into the sea, the one time missing me with their bomb drop, but getting me with their plane crash...
So if you spend much time at PD, especially with smooth seas, you don't even have to stick your periscope up to get bombed and sunk. This is also a "feature" of TMO, and was carried over from there to FOTRS by AOTD_MadMax. FotRSU has kept it...
