[sailcat]

Ben, I just went through this also. Keeping the boat on the trailer is not the best way to do this. When the boat is in the water it settles different than when on the trailer. The trailer will have different pressure points than blocking it.
Trayder is on the money with making sure the boat is straight. Mine had an inch and a half corkscrew in it when I started.
I put a 75 gallon tank in my 20' with a 200 and I have plenty of gas for the day.