Sometimes You've got to be careful.
A few years ago my father and I went out with a friend in his 23 ft penn yan. Relatively speaking the waves weren't bad but my father started heaving so many times you couldn't count. Kept telling us he was ok and keep fishing. A little later we boated a 28# king which he took a picture of me holding. 10 minutes later he asked me if we caught any fish? then he started asking what time it was every 30 seconds to a minute?? Long story short, something in his head had snapped due to the violence of the vomiting. Obviously, we pulled and ran in immediately. Drove to the hospital, Dr. said that it was Trans-global amnesia due to the stress the vomiting put on his system. By the time we were done at the hospital he was back to normal but he still doesn't remember ANY of the fishing trip, not even taking the pictures. The waves were maybe 2-3 ft and we were in a good sized boat. All I can say is everyone is different when it comes to being seasick. I have been there when I am puking my guts out but don't ever want to quit, but when my Dad started asking me what time it was every 30 seconds it scared the hell out of me.