Using a Lithium-ion battery, some CO2 scrubbers and oxygen cells they are able to extend the amount of time you are able to spend under the water. No word on how long you can stay underwater as that’s got to be at least partly depending on the size of battery and size of your air tanks and how you breathe, but sometimes even just a half hour is enough to see the fish you went down looking for in the first place.
One potential downside is if this Li-Ion battery goes bad and explodes, you’ve pretty much got nothing but more fuel for the explosion attached to your back, which is good if you went down on your own as it means there’ll be no mistaking you’re a goner, but bad if you have dive buddies as the shock wave could mess them up pretty bad too. I like the idea of extending the amount of time I can stay underwater though, regardless of the risks.
Put me on Extreme Makeover and tell’em I want gills, forget all this dentistry, face lift, augmentation crap, I want an actually extreme makeover. If that happens, no one’s allowed to call me any name of another famous fish, no Flipper, Shamu, Free Willy, or any of that.