Scuba tanks can only supply oxygen for a limited amount of time. We investigate whether an algae suit can be realized that uses photosynthesis of algae to supply a diver with oxygen while the diver supplies the algae with carbon dioxide. An optimized, closed system in which the diver and the algae form a symbiosis should extend the oxygen supply dramatically. Initially, we want to find out which variety and quantity of algae would be able to cover the oxygen requirements of a human under what conditions.