A bean boat is a person that creates problems for themselves and others by simply attempting to do the things that they've been asked to do.
Like, try making a boat out of beans - it wont stick, the beans will separate and sink, and only the beans that float are the hollow beans that have been infected with insects.
"I asked him to paint the door but somehow he managed to break the door , sprain his wrist AND fuck the carpet all at once, fucking bean boat."