Fine then go take your nice BL motor and BL speed control and hotwire the little sob up in your boat. I don't give a crap if you burn either one of them up, it's not my money.

You asked the questions, just because you didn't get an answer that you wanted to hear doesn't mean anyone is being negative and looking down upon you.

If I went somewhere and asked if it'd be ok to build a house out of 1X3's and they said, "No the house will fall down" it doesn't mean they're being negative.

There are gear reduction units out there. I'm sure you could find something to make it work. You'll have to custom fabricate a mount for your gear box and then get or make a coupler that will attatch the output shaft of your gear box to the propshaft. Untill you get all of your components together, there's no way to tell you what exactly you'll need to make it all work. In reality, it'd be a lot easier, faster, more effecient, and not much less of the same cost to use the correct motor and speed control for the application. But, you can make what you've got work.