As soon as you got her on the trailer you should of kept her running and looed for the source. Now you will just be guessing. It can either come from the engine cooling system (water pump, hose,eng, ballast) or from a boat hull leak (exhaust, bolts anything that pokes thru the hull. Hook the water hose up to her and try it again. If that doesnt leak anywhere start looking at the hull places. Good luck man. Jet