Typically, it's good practice to keep one's electronics away from water, but with the Hydralight, water is a necessity. The rugged flashlight uses salt water in order to power its energy cells, making it the ideal light for coastal camping adventures.
Not only does the Hydralight use water to power itself, offering up a natural source of energy, but it also means that users need never contribute to e-waste in the form of batteries, which are notoriously difficult to dispose of and recycle. If kept in good conditions, the Hydralight should last for up to 25 or more years, and dunking the energy cells in salt water should charge up the light for up to 250 hours.
Campers need not live near a coast in order to make use of the Hydralight, either. Its cells can operate with a simple mixture of table salt and water as well.