Might I suggest the Glo-Toob fx as a strobe/electrical lightstick. Available from Brigade Quartermaster or TAD gear (sorry I don't have a clue as how to link stuff, need to get with the misses and fix that). The glo-toob is waterproof to a mere 11,000 feet making it a pretty good choice for water activities. The fx model is "programmable" with 7 light pattern options from constant on, several intermitant patters, and the sos pattern. They also make a basic on/off model. Comes in a variety of led color choices.

-Bill Liptak