I was cleaning my tank yesterday in preparation for being out of town for a week and I fell into my Kessil gooseneck and ended up dunking it in my tank. I disassembled everything and swabbed the PCB with distiller water and isopropyl alcohol. The boards seem pretty water resistant, as they are coated with some kind of rubber sealant. I couldn't clean the cooling fins, however, as they were too narrow for even a cotton swab. I figure they are eventually going to get coated in salt anyway. The light still works fine, though I won't get to monitor it for a week. It seems as though these units are built to be very water and salt resistant.