Ive had 2:
First one was in 1997 in Paris with my high school. We were on a double decker coach and went under a low tunnel. The roof was ripped off and I was on the top deck.

Second time was in 2002 on a boat coming into Wales. The waves were coming up to the deck windows and 4 tug boats had to come and help pull us into port!

Both very unpleasant.