Can Anyone Help With A Riddle

This riddle was posted on a another forum I am a member of and it's been driving the whole forum nuts. I have cut and pasted it exactly as it was posted. Any assistance greatly appreciated.

right first off i will NOT tell anyone the answer unless they have it right. so dont ask. secondly all the info you need is in the riddle, disregard anything that is not in the riddle, so dont say "it washed up on the shore" cos i never mentioned a shore in the riddle, dont ask me for any more info cos there is none. the only reply youll get to that is "the answer is in the words". lastlyif you tell other people or put this message in other forums please remember and credit who it belongs to sillybuttons™ and DO NOT change any part of it, it has to stay as it is otherwise the answer cant be found. thanks and have fun.

A small boy went for a walk in the park with his grandfathers hat on. He took a boat out on a lake, the boat capsized, the boy was drown. What became of the old mans hat?

this is a very hard riddle but you will kick yourself IF you figure it out because its obvious. its so obvious its always overlooked and thats what makes it hard.