The PRISM, or Peter Ready's Incredible Steam Machine, is a fully closed-circuit rebreather designed to recycle exhaled oxygen, which means quite simply that divers can stay submerged for longer. This makes it an ideal tool for open ocean, cave and wreck diving, especially as it can be equipped with 13, 19, or 30 cubic-feet-capacity cylinders.
And because scrubbing the air (rather than breathing it out) creates significantly fewer bubbles, you’re far less likely to disturb sealife. Tested to depths of 100 metres, the Prism 2 also requires the least WOB effort (Work of Breathing) of any mixed gas CCR on the market at just 0.94 joules per litre.
From £7,040, rebreathersuk.com