Say hello to some bright new ideas for night dives. One big downside of the light stick is that it becomes trash after a single use, while electric lights are reusable. Another is that light sticks sometimes discharge in the package or are triggered accidentally, turning them into duds at the dive site. Persistent Problems Actually, electric lights aren't the perfect solution either.
Dead batteries are trash, too, though less visible.
Batteries hide their morsels of lead in a landfill somewhere, assuming all of us can resist the temptation to hear them plunk into the water. A flashing light is far more noticeable than a steady one of the same brightness. I viewed all these lights together, plus a couple of light sticks, from the same distance under water, and the difference was striking. LEDs are brighter than before, and available in white and orange as well as red. They don't break if you drop the light, and they're very gentle on batteries.