i'm sure you allready got it fixed up, but the liquid stitching for stuff similar to this would be perfect, && its waterproof
Surgical adhesive doesn't work well when the skin is under much tension at all and that area is always under tension. But, a combo of sutures with a little surgical adhesive over the top isn't a bad idea. The drawback of surgical adhesive is that it does tend to hold fluids in and sometimes (see below) that can limit healing. A little seepage isn't necessarily a bad thing, and I've been known to
almost completely close a lac, just so the bottom end could drain a little. It will actually heal faster sometimes, if you leave a little bit of a drain hole.
I cut my ankle at the Chickenbone ride, they used the liquid bandage (superglue), I wish they had stitched it now, it took forever to heal and close up, alot of fluid gets built up under the glue making it hard for the cut to close up.
That's actually a pretty difficult area to get to heal no matter what.
I just happen to have a friend that had a similar lac (similar to the pics) and it got closed (with a little tiny gap at the bottom for drainage) with sutures only. He actually had wetsuit material stuck on the bone and it didn't even cut his wetsuit, just his shin (he slammed his shin into the back of the tray). It healed very well and pretty quickly. With, say, . . . a dog, . . that had a similar lac, I would make sure that "the dog" got started on an appropriate antibiotic for 5-7 days as a preventative. And, as pointed out above by Tor*p*do, that tetanus shot is important.
Oh, and the waterproof bandages by 3M are made with a clear, plastic material that is pretty waterproof as long as it's covered by your wetsuit or some other protection. If it's anywhere that the water can hit it, the water will peel it right off. I've used it under gloves and it stays on surprisingly well for the first hour or so. Longer than that and nothing's going to stay, not even surgical adhesive.