I pitchpoled my boat this year and it turtled. Since then I have had water in my Comptip. I tried all angles and all positions to find a place where it leaked for the water to drain out with no luck. I finally drilled a small hole at the top for the water to drain. I ended up with about a gallon when it was done draining. Now I need to plug the hole. I thought about using a screw with a flat rubber washer or maybe just putting a rivet in. Any suggestions?

Regardless of what you plug the hole with, shouldn’t you determine how the water got in the mast and repair that?

No, never, if you can't see the hole it isn't there...

I did have a hole in the main part of the mast at one of the rivets which I sealed with silicone. The Comptip I figure got water in it from the pressure when the boat was turtled.

How long were you turtled for?

Leaks in masts during a turtle may be hard to find. The underwater pressure may overcome a loose seal. That seal may re-seat under normal air pressure. The glass fibers on on the seams of the older CompTips can also seep water in over time. We seal there with resin these days. These seams also can suck in humid air which then condensates inside the tip.