Saw it happen once on a liveaboard, woman blew a neck seal, glue would take 24 hours to set even hanging in the engine room but the boat did have a 7 mil she could borrow. The good news was during the surface intervale a humpback and calf showed up escorted by dolphins and buzzed by seals. Snorkeling with them in a wetsuit is much easier than it would have been in the dry suite (dry suit, gloves and hood = suite)