[Gerry Zagorski]

Great advice above. I too would want to know where all that water came from in the first place, otherwise you are just treating the symptom and not the problem.

20 gallons is a lot of water and that volume of water would not be caused by normal condensation in the tank from a winter lay up.

I'd be checking the fuel tank as suggested above. You don't want water in your fuel or fuel in your bildge. Either one could lead to much bigger issues if it's not taken care of.

I had a fuel tank leak in one of my old boats.... The tank was easy to get to so I took it out, bought it to a place that also services radiators where they tested it, found the leaks and had a special process where they coated the tank inside and out and it stopped the leaks.