John, Thanks for that mate.
I think I feel more comfortable in placing ply around rudders and prop shafts for reinforcement seeing that their are only two layers of 0.6mm ply.
The prop tubes in the photo are only their for fitment indications ie, see where the prop tubes end up. The center shaft is only 14 inches long and will receive longer shafts later this week.
My only concern is that the center prop shaft is only about 1/2 inch above keel. I will need to place some ply in the hull to mount the motors (and probably on aluminium brackets) and would like to have clearance from the hull for air flow and water cooling coils.
The motors I am currently looking at are the Graupner 700BB Turbo's (7.2 - 19.2v) and MFA 850's which will be powered by a Gel Cell.
I am also investigating the "Darke Horse" Speed 700, 3:1 Ratio Planetary Marine Motors (high voltage, low current drain). Apparently, these motors are suited to this type of model and can operate from 6V to 28V using up to 20 Nimh Cells.
Electronics, will probably use ACTion's P94 setup but if this turns out unsuitable, the unit will be ideal for my 2 shaft Freemantle Class Patrol Boat (arriving shortly)..
I think I will be a lot happier to have the motors in hand so I can determine final length and placement of prop shafts before I set them in permanently...
John and forum members, please feel free to comment - it's all helpful and appreciated
Martin doon under