Single Screw work boat (STOPED, description bellow)

2018 12 27: This project is stopped and won't be developed. There is a critical error in design: screw is too high and at higher rpms generate more buzz than thurst. Boat is too small to make it go deeper so if you'll develop it further, either screw deeper or boat a little higher is it could go a little deeper without a a risk to sink.

2017 07 23: applied putty twice, painted twice (not sure if it was worth doing so) and applied yacht lacquer. Buoyancy seems just fine, 2,5 kg is a the limit.