Water and Lava bug

So I was exploring on Minecraft and I noticed that when I was standing on my boat, my bubble bar appeared. I was not in the water. This bug happens with lava as well.

How to reproduce:

1. Find a river or ocean in an infinite world. (Must be 3+ blocks deep) 
2. Get in the water.
3. /summon boat
4. /gamemode 0
5. Walk on the boat near the edge, but do not go in the water. 

Expected results: Your bubble bar doesn’t appear.

Observed results: Your bubble bar appears.