HYDRO-LUNG

Hydro-lung was one of the first nanovirus applications.  When the nanovirus is injected into the character the nanovirus  attaches to the alveoli in the lungs and allows the lungs to extract oxygen directly from any type of water.

Activating the nanovirus is a rather unpleasant experience, you gain the staggered condition the first round you begin breathing water.  After overcoming the fear of drowning and your body’s natural responses to inhaling water, you can act normally.  These nanite allow you to breath underwater as long as you are submerged.  Deactivating the nanovirus is equally unpleasant. You gain the staggered condition while forcing the water out of your lungs.  If you need to briefly come to the surface it is possible to hold your breath or in this case hold your water while operating out of the water.  See The Starfinder Role Playing Game for rules on holding your breath.