When you fall from a boat then get out, you will teleport to the place last standing then 10-15 seconds later, take fall damage.In another case. You will fall from the boat teleport than get stuck where you last stood. In another case you will step out of the boat teleport and the boat teleports with you. In another case you fall and die from fall damage and your spawn is off by 15 blocks.IN ANOTHER CASE when you get in the boat the boat falls through the block supporting it, you fall, teleport, and walk off with out a scratch.