It looks more than that from that pic so fair enough.
The reason for doing that is preventing the hull from getting a hook in it over time. The way to fix it is move the axles and the boat forward all in one go.
It is not bmw, bwm is the make if that is what it is. It is easy to tell if it is hypalon, have a look on http://www.polymarine.com/advice/pvc-or-hypalon/
Edit- may be the picture but is it hooked now? Not a big job to fix the trailer though so don't worry about that.