Instant death and boat destroyed

What I expected to happen was...: a normal peaceful boat ride.

What actually happened was...:
I died, the boat was destroyed, and I was sent the message "so-and-so hit the ground too hard" even though I was in a boat, floating on the ocean, and not touching any solid blocks. This does not happen every time I get in a boat, but often enough to be EXTREMELY ANNOYING.

Steps to Reproduce:
1. Get in boat
2. Row for a little while.
3. Stop and sit.
4. Die.