PT, while playing with Realistic Sailing enabled, I think I may have found a bug in the mod.
Everything works fine unless you're in a IID U-boat running with "decks awash". The ocean spray coming over the conning tower gets locked into a loop that will not shut off the spray between waves.
I think I traced it to a negative value set for the node trigger in 'Turm2D_1_hd.dat'.
The fix was easy, just open up the file in S3D, and then browse to the entry named '229: Node - Turm2D_1_spray'. Look at the Z value in Offset and remove the minus sign in front of the number so it is a positive value like the X and Y values already are.