Anyone know about electric engines that can be used down too 50 meters 12-24v with enough trust too move 25-40kg sideways ( have a wire from surface too hold it at the depthes needed ) ?
Hopefully a easy plugg and play engine !
Will use powersupply from surface

Did you post in the submarine section ? I suspect some of the guys there may have insight.

I know on my Crawlers, the motors have been submerged for minutes at a time repeated and ran fine as long as they were oiled routinely and cleaned if using in muddy water. Shoot I have submerged the battery and the motors and they ran fine. Electric motors are a lot of the time broken in underwater. Never ran them for extended periods of time underwater but I know they won't fail immediately and they would prolly be fine. The motors I am running are 55t Integy lath motors.