Nice Title ...COUGH*NOT*COUGH
Lesson Number 1: DONT SAVE IN PATROL
Especialy NOT while beeing attacked!
Especialy NOT Submerged
Especialy NOT in really bad wheater
If you really NEED to save then:
be on surface , go slow forward and wait till the sea turns calm
then you have a lesser risk of getting a Bugged patrol when you reload the game.
FYI : I never had a problem with my Save/Load function. when I do the things above