Boats glitch through walls

Steps to recreate:

1. Make an ice path high from the surface (Like a bridge) .  
2. Place full solid blocks on the both sides of the path, leave the bottom of the walls empty (so that there is empty space under the walls next to this path which the boat can fall down from).
3. Place a boat on top of the ice path, inside the walls. 
4. Push the boat forward, or enter the boat and move forward while turning left/right.

---

Original description
Boats glitch trough walls on ice when you go straight while turning left/right.