In recent years, the German navy has demonstrated hydrogen fuel cell powered submarines with endurance comparable to their nuclear equivalents. This is exciting for a number of reasons, not the least of which is the possibility of reducing the use of nuclear fuel which presents serious disposal problems. The compact naval reactors used aboard modern submarines consume their fuel in between five and twenty years, depending on model. This ensures their dependence on shore support, although to an extent that has been greatly reduced since the days of the diesel electric submarine. This dependence can be greatly reduced by the use of hydrothermally powered stationary emplacements on the ocean floor at a depth of between three hundred and one thousand feet. Each facility would exploit hydrothermal energy to separate hydrogen and oxygen from sea water, storing both in large cylindrical tanks. This would permit fuel cell powered submarines to operate independently of the shore for much greater periods, when combined with my other related idea, subsea food resupply depots. With both food and fuel depots distributed underwater along the continental shelf, a hypothetical US Navy fleet of fuel cell powered submarines could operate continuously without having to surface until the food depots are depleted, which could take as long as a hundred years. This assumes also that the fuel cells are designed for periodic restoration, using supplies also contained in these undersea depots. These measures, implemented together, would finally permit long term undersea warfare without topside support, sustainable even in the event that the USA is devastated by nuclear or biological attack. In this worst case scenario our nuclear navy would remain unaffected, with no decrease in operational capacity for up to or slightly in excess of a human lifespan.