At last found time to continue, anyone else find that life gets in the way of the real world?
Got the electrics in. Used a 385 motor, 2mm shaft & 20mm 3 blade plastic prop. Power from 5 x Ni-mh batteries and a Mtroniks speed control.
Only tested in the bath so far (waiting for the rising water to reach the back door
Seems to go well and I can do a three point turn in the bath!
If when I try it on open water I feel the need to increase power/speed changing from plastic to brass will increase the pitch.