Any ideas on warding off flies on a boat during the day? I've tried sprays like OFF and I can take a bath in the stuff and it won't stop the flies. I got some of the coil mosquito repellent things that smolder to try. I thought about getting one of those bug zapper lights but my hunch is they won't work too well during the day since the bugs are attracted to the light = not real affective when it is light out. Any other types of zappers that work well for flies during the day?