The Hydra-Light PL-500 is a high-tech personal lantern that is powered by fuel cells rather than conventional sources of portable energy.
This lantern's heart is comprised of a carbon film cathode and a special high energy-density alloy anode. When exposed to salt water, the anode begins to oxidize, causing it to release electrical current that can be exploited as a source of energy. The anode works with seawater or even water mixed with regular table salt.
The problem with regular lanterns is that you tend not to use them often, but they are prone to being drained of battery or power just when you need to use them. The Hydra-Light PL-500 gets around this problem with its use of salt water, ensuring you always have peace of mind and aren't left in the dark about your lantern's usability.