23' Tsunami small deck core repair ?

[shine]

That is basically how I would do it. I would use milled glass and pour the epoxy in stages. The milled epoxy will give the plug a lot of strength, but it is not thixotropic so the epoxy will still flow and fill all the crevasses. You could even add a little chopped glass if the hole is big enough. Pour in some epoxy, then take a sander (with no paper) and vibrate the area to let air bubbles work out.