Blow out the components with compressed air, get a 5 pound bag of white rice, start dismantling and put all in the rice. This should be done immediately after the event. Wait three days and pull everything out and blow with compressed air and reassemble.
Naw. You're screwed, man. The battery is what screws you. Actually, screws the solo, but same thing. The electricity flows and the water causes it to short out. It sux, for sure. There's a battery in the GPS assembly as well. Not to mention the battery in the GoPro, too. Sorry for the reality poat. Perhaps you'll do much better than I have done when my solo's have taken baths.