Thanks for the information.
Boat is a Sea Commander (Aerokit)
I’m fitting J Perkins M4 - 45S Boat Propeller
Will follow your recommendations re a fuse
Thanks
Paul

Motor Spec
This is a high power '600' type motor (36mm diameter body, 3.17mm shaft, slightly longer than '550' type motors) suitable for operation at between 3V and 12V DC. The motors are usually found in cordless drills running at a nominal 9.6V but operation at 12V is possible so long as the load and duty cycle are not too high. The motors will draw a high current and so you should ensure that the power source and control hardware that you are using can withstand this.
Description
As with any DC permanent magnet motor this motor will exhibit different characteristics depending upon the voltage (and current) applied to it. To change the rotation direction swap the polarity of the current to the motor tabs. The copper motor tabs are 4.8mm wide male spade connectors, which are easy to fit 4.8mm female spade connectors to or to solder on to. An option is provided for two 500mm silicone-insulated power leads to be supplied ready-soldered to the motor.

The motor features a built-in cooling fan, which due to the high power output of the motor is essential for cooling (and so the two air vents should not be covered). Do not allow the motor to stall as it is likely to overheat quickly.
Technical
Approximate motor performance at no-load:

4.8V - 1.4A - 9200 RPM

6V - 1.5A - 11,500 RPM

7.2V - 1.7A - 13,800 RPM

9V - 1.9A - 17250 RPM

12V - 2.3A - 23,000 RPM

Be aware that the motor is capable of high torque output but the current can easily exceed 40A-50A under load and could hit 80A if stalled at 12V. Ensure that stall situations are prevented by using either a fuse or current limiter in series with the motor.

Thanks Doug
Motor spec is:
Operating range: 4.8 – 12v DC
Overall Length: 90mm including solder tags
Diameter: 38mm (Max)
Free Load Drain: 2.154 A @ 9.6v
Maximum Efficiency drain: 14.98 A
Motor shaft: 3.175mm
Speed: 20,384RPM @ 9.6v
Maximum Output Power: 106.65 watts
Weight: 240g
Stall Torque: 412 mNm

Thanks
But what is the voltage of 6-9 cells

I will be using a Hobby wing WP Quicrun 1060 ESC to control a Johnson 683 Brushed Motor.
The specifications for the ESC states that 6-9 cells nimh can be used, but does not state voltage.
Can anyone tell me max voltage of the ESC so I can purchase correct batteries.

http://www.hobbywing.com/goods.php?id=358

Martin555 asked me for photos of the cabin roof that this enquiry refers to and that’s what I provided.
Thanks for all the help and replies 👍

R/C is
AUSTAR AX6S 2.4G 4CH Transmitter Radio Remote Control & Receiver

That’s the main cabin roof

Would magnets have any effect to the R/C signal?

Thanks
I did consider that and why not it’s easy to fit and allows easy access
👍

How do you secure removable ‘roofs’, to stop them being blown off, or lost during operation of the boat

I got a Sea Commander in 1974, I was 14 then, and my father helped me build it.
Unfortunately I didn’t complete it and it was put away. Now is a good time to complete it and I am getting all R/C equipment and fittings together to complete it.