Actually, to prove something works it does have to be quantitatively defined.
Your imagined reality is not fact unless you can define it with solid laws of physics.
I think you are a bit confused. My imagined reality? How about I attempt to clear this up.
The OP wants to use electricity to move his boat. Then with that motion, generate electricity to power that same motor that makes the motion to harvest the energy to make the motion etc.
That system will come to an end. I assume you know this to be true without me giving you numbers. Or is that what you call my imagined reality? You don't really think he power his boat forever with his set up do you?
So he transfers power to the water and makes motion. Then there is a turbine up front creating drag which his motor needs to work harder to overcome to maintain motion. That turbine captures motion energy with a LOSS. Then that turbine transfers to a generator which has another LOSS.
Hook the generator right up to the motor and you don't have the TURBINE LOSS. Just the generator loss. Either way that boat is going to stop sooner or later.