Motor Boat RC enlarged (experimental)

I know, it is not a beauty. It is just an easy way to enlarge the boat
http://www.thingiverse.com/thing:272132
to make it big enough to carry the strong and heavy outrunner motor which I use for my airplane
http://www.thingiverse.com/thing:86982
I simply printed a 100 mm extension and daubed it between bow and stern part - with tape as usual ;-)
At first I tried a 35 mm surface propeller which I got from a friend. This Propeller is more effective than my printed propeller. It needs le