I kept a flattie one day off Point Fermin in LA. It was on a stringer of sorts that I had. Anyway, a seal figured out I had a fish with me. I heard his wet exhale behind me and quickly pulled the fish up on top pf my tubes apron. The seal circled and cirled, swimming underneath and around me. He followed me all the way to the beach and stayed in ankle high water just staring at me until I walked off with my catch.
I never kept any fish, while tubing in the salt, after that.

I like the idea of this tourney though. What I'd recommend for anyone with the means to do it, is use a kickboat. You can put a livewell on it, completely out of the water where the seals can't get at it.(or smell it) Use a bilge pump to keep the water fresh and aerated. And if the rules allowed, you could cull fish without worrying about their mortality and release them at the end of the event or have a killer BBQ. Pass the vinegar and tartar sauce!! Mmmmm....fresh white sea bass.

I sure wish I could fish your tourney but I live too far away right now. (north of SF)
Tight lines & have fun!

Chris