Rebreathers have been steadily making their way into the sport diving market for a number of years now, so this is really nothing new. Rebreathers work very differently from bottled gas systems in that they scrub the CO2 out of the air that you exhale and recycle it. It means that you can potentially stay underwater for longer, but perhaps the biggest benefit is containing your air.
By containing your air you eliminate bubbles which can be distracting, disorienting and can disturb fish. You cannot really put a minute value on how long someone can stay underwater, every person is different. Things like muscle mass, body size and breathing rate come into play. Rebreathers will keep you down for long enough. Poseidon claims that you will be able to stay underwater for twice as long as dive tables allow.
Word on the street is that the Poseidon Discovery Mk VI is selling for about $7400, not to bad considering what you get for your money. You also have to factor in the training costs, but they are worth it if diving is your thing.
Sources: Poseidon, Geekologie, DVICE, PopSci
Your goldfish deserve a better home than the algae filled fishbowl you have sitting on your kitchen counter. One easy way to give them a lodging upgrade and also add some art to your pad is with the 
