-- Last Updated: Oct-23-12 10:48 AM EST --
I suspect Royalex is prone to these types of puncture holes. I repaired one once that had a softball size puncture. A white pine tree limb fell vertically and punched right through the canoe.
I glued the remaining Royalex puzzle pieces back together with G-flex. I filled any remaining missing puzzle piece areas with thickened G-flex,and then patched the inside with fiberglass and patched the outside with fiberglass. I filled the fiberglass weave with G-flex, sanded and painted with Krylon to protect the epoxy.
As far as I know, the repair has held up fine, but the family uses the canoe for flatwater trips pretty much exclusively.
The hole was smaller than yours and not on the turn of the bilge, which may complicate things.