posted 03-19-2014 01:31 PM ET (US)     

1998 Outrage 17

My boat has been out of the water for a couple of years. I have washed it several times after sealing the seat screw holes.

Today I unscrewed a plastic plug of some sort in the cockpit sump located behind the pilot seat. This is a locker on the deck floor. I discovered some mud as I stuck a screwdriver in there. I believe this is the fuel tank cavity drain. I did not smell any fuel.

How does water get in there to begin with?
What is best method of cleaning this drain area to get all the mud out and make sure no water is getting in there?
What is the best tool to use to open this plastic screw? I used two flat-head screwdrivers simultaneously to unscrew it.