(Sorry for the bad English D🙂
This bug affects to both game modes.
If you put a boat, wait 5-6 seconds and you ride the boat, you will cross the block and fell down. When you dismount of the boat, you appear on you have rided it. If you die/reload the world, the boat will be on the original pisition.
Video by me: http://youtu.be/8wuCI7-_O2E
Duplicate of MC-811.