Have a look at the late Dave Milbourn’s article “But I don’t understand electronics” in the Hints & Tips on the forum. Its very good & gives a table of different motors & their applications at the end.

Stephen

I would suggest a low Kv brushless would be the “modern” replacement for a geared motor. Something like cheap 28mm outrunner of 1000Kv would power a decent size prop without breaking sweat. Not sure how big a prop we are talking here?

On a 7.2v stick, you would only be talking of 7000 rpm.  One thing a geared unit does get you is good low speed control. I have a big 2 blade 60mm paddle shaped prop on the London powered by a 2.5:1 geared 540 motor and you can get some very low revs on it, barely moving (so you can admire the prop).

Obviously towing a trawl net calls for oomph, and these cheap brushless deliver well over 100 watts normally which is good compared to the output of a “normal ” 540, or even a 600.

Ashley