I am currently keeping my boat on a private lake and the house doesn't have a ramp so i don't plan to take the boat out often. I was wondering if you are allowed to use soap in a lake? Also there is no hose near the boat so would it make sense to hook up my fly high pump to a hose and use lake water to wash it down? The house is under construction so the boat gets very dirty very fast.

Depends on the soap, some is meant to not harm the environment. I don't know of any brands like this but I would not recommend using just any soap unless you don't care about polluting and then I suppose just go nuts.

I use SeaSafe Boat wash by Starbrite, even here at the house. <BR> <BR>"Biodegradable formula removes dirt, grease, oil, fish blood, and stains with no hard rubbing or scrubbing. Use on fiberglass, paint, rubber, plastic and metal surfaces. Concentrated. Quart."