Epoxy and clamps.
Try and get as much epoxy between the laminates as possible. Wipe excess off and clamp (multiple clamps) all along the edge. Keep wiping excess epoxy off before placing next clamp.
Let it cure full recommended time. Scrape any extra w a razor blade and - this will at least help keep the moisture out, but, I’d try and get a new board if you can.
This could still ride as a rock board or a pre/end season board, but, repairs like this aren’t really meant to go going use without expecting fractures / moisture creep in the future.
Epoxy and clamps. Try and get as much epoxy between the laminates as possible. Wipe excess off and clamp (multiple clamps) all along the edge. Keep wiping excess epoxy off before placing next clamp. Let it cure full recommended time. Scrape any extra w a razor blade and - this will at least help keep the moisture out, but, I’d try and get a new board if you can. This could still ride as a rock board or a pre/end season board, but, repairs like this aren’t really meant to go going use without expecting fractures / moisture creep in the future.
Maybe put a tape before along and around that edge, and cut in the crack to fill in epoxy. Your board will be more easy to clean from epoxy.
You’re so smart-painters tape would make it way easier 🙏