There is no (easy) way to retrieve a boat (in MCPE) once it is placed in water. This behavior is particularly bothersome when you have a pet on board with you. If you try to bash on the boat with anything, you board it instead of retrieving it. The only way I've found to retrieve the boat is to set it on fire, which of couse damages (kills, if you're not quick with the water bucket) the poor animal. Do we need a "Retrieve" button, say if you have an axe in hand?