Doesn't look like a boat, looks like a tree that died and fell into the the loch. You can see what looks like branches and trees that have been drifting on the surface of a body of water for a while turn white in color.
It's a good thing that Sir Cort Godfrey of the Nessie Alliance summoned the help of Scotland's local wizards to cast a protective spell over the lake and its local residents and all those who seek for the peaceful existence of our underwater ally. Because now we are still able to partake in the viewing of such a magnificent creature.