Agree with glass. This is an easy glass project. Be very careful with "5-minute" epoxies. Most of them are "water resistant" not waterproof and don't belong on a boat, even above the waterline. In general, the longer it takes an epoxy to harden, the more durable and resistant it will be.
Sand or grind the area for several inches around the hole. Cover the hole with a piece of gorilla tape with minimal overlap at the edges, or a piece of flexible plastic "tacked" in place with some JB Kwik. This will keep the resin from leaking inside the trunk, then glass over the hole. Use several layers of glass fabric and West epoxy, overlapping with increasing size in each successive layer.
If you want to do a quick job, use thickened epoxy as mitiempo suggests. If it's above the waterline and not structural, that's probably fine.
1977 C&C 30 Mk 1 hailing from Port Clinton, Ohio
Last edited by msmith10; 01-18-2012 at 07:03 PM.