Peter - There are other members much more qualified to give you recommendations on motors for your boats - actually tried using an old Bosch drill motor - high torque but very slow AND very high current draw - too much for a 40amp ESC on 12v
So was advising you very much on personal experience and knowledge gained afterwards.

Would suggest that you start another thread for advice specifically on motors/esc for the models you have - certain you will get a good response here

Ok and thanks. I might give it to a friend who does have a large but very underpowered tug.

Will go by the recommendations for the boat - cheaper in the long run as well for a better result.

The motors in those are usually very high current drain - so high powered ESC (expensive) needed and relatively short duration . Have heard of drills being used to power LARGE tugs - with the gearing enabling them to drive very large props (same as diesels in 1/1 scale) . Not sure how fast the motor would be as it would be most likely be wound for torque and not rpm - you need a high rpm motor for something like the Sea Commander to get a reasonable speed from it.