Dude

!!!! Take it to a shop or somebody that can do work on boards!!!! Have a gromet installed in the deck. Tie a string and push it through from the fin box and ram the knotted end into the box your looped string will sit atop your deck and wait for your leash. This is by far the strongest leash atachment, you'd have to rip your center box through the surfboard to get "plug failure". It would cost at most $50.00 (should be about $30.00) but even if it were $100.00 is the surfboard worth that much??? I'm thinking it's a new board but even if it's not why would you want to half azz it??? and have larger problems (like water leakage and delam)?? Just from a did'nt do it right. Do it right not twice........