Noob question hull cap separation?

[SkunkBoat]

if you think the boat is listing because of a leak in the seam under the rubrail, you need to look for water that is trapped and not draining to the rear bilge pump.

The list may be unrelated to the seam but you need to look for a cause.

You can remove the gunnel boxes. That will give you a look at some of it from the inside. You could have someone spray a hose at the rubrail while you look at the inside.

newer V20s had foam outside of the stringers. Old V20s did not have foam and the holes for bilge water could be clogged.