Describe the bug
While mounted on a horse/hippocampus or when a siren attempts to swim in water, all of them go super fast.

To Reproduce
Steps to reproduce the behavior:

1. Join a server
2. Tame a horse/hippocampus
3. ride the mount in water
4. experience the g force

Expected behavior

I expect mounts and mobs to not go extremely fast in water.

Info (please complete the following information):

• Modpack Version: 3.0 beta 3
• Server or Singleplayer: server
• Version the world was created on: 3.0 beta 3

Additional context
I assume that issue #623 is similar to this one. Also, Piranhas also go super fast too.

This is no longer an issue in v.3.1.1a, so it may be closed.

Possible fix: 19aeda1