My cousin flew his RN helio into the sea way back. Low and fast returning from an exercise in calm conditions. He got out, but not the observer.
Early in WW11, the old man was stationed defending Scapa Flow. While flying a Master with a Sgt Pilot in the other seat, he noticed they were very low over the water. Low enough tos see prop wash on the surface
He grabbed to stick, only to find it loose. They both thought the other was flying the a/c..... Something got lost in the Gosport tubes.