I've looked through the library and didn't find any info in there about using solar lights at night on your boat. There wouldn't be any drain on the batteries using them. Although I've never had any problem of drained batteries by using the anchor light in the back there is always that possibility. Although they don't put out a lot of light but t should light up the deck of the boat if you are doing any moving around and maybe you won't knock over your cup of coffee or can of beer. Heaven forbid! But they should provide plenty of light to rebait or cut some bait or even drag out a bologna sandwich from the cooler. Thought it might be interesting to try sometime. Maybe rig up a way to position them in a rod holder or make some kind of rig to install them where they would provide light where ever you want it. And if you wanted darkness then just put a paper lunch sack over them to at least dim the light. Any ideas or suggestion?