Someone in another thread mentioned (sorry, old aged brain here, can't remember who. Tim, maybe?) that one of the unsung glories of the SL REOs, is that you can easily thread a piece of leather(paracord, plastic coated steel cable, whatever) through the slots for a lanyard. I'm thinking you could attach a plastic coated steel cable 4 or 5 feet long and secure it to the boat. That would at least prevent any "REO overboard!" type mishaps. Make it extra long so you don't have to unfasten it to use it. It would also discourage folks from slipping it in their pocket and walking off with it.
Other than that, and protecting the contacts, you might want an extra sealed container for spares (rm2, juice, batteries).