: Two suggestions : A; Can you close the crack with two or three ratchet tie
: downs?? ( wrapped around the hull )

: If so pull a little epoxy into the crack with a Shop vac from the other side,
: and then strap it up, and ... gently ... tighten the ratchets. When the
: epoxy cures, add your glass strips from the inside.

: B. To stop a tension crack from spreading, drill a 1/16the dia hole at either
: end of the crack. This will relieve any furthur tension spreading of the
: crack. The tiny holes will easily fill from the outside with the epoxy

Plywood cracks won't extend on their own due to the multiply plys running in different directions. Good advice for monolithic materials though.

Bill H.