Interesting project. I swear I have seen it done before on a SIB, with an electric trolling motor mounted to the bow, although not remotely controlled.
The drill bit is kinda confusing. Is it a 1:1 or geared? In other words how fast is it going to react? How do you plan to control throttle? The DPDT switch is momentary contact right?
How come there is no room on the transom? Are there wheels?