Boats keep momentum after dismounting and mounting it

I recently noticed while riding a boat that it saves momentum when you dismount it.

This doesn't save when you reload the world.

Steps to Reproduce:

1. Get a boat on ice and mount it.
2. Press and hold the right/left key until you go fast enough to notice the bug.
3. Dismount the boat right when you stop holding the right/left key.
4. Mount it again.

Observed Results:

The boat keeps spinning. (Only when you mount it)

Expected Results:
The boat loses all momentum. / Continues spinning whilst you're not riding it.