Once reserved for underwater warfare, a scuba-diving device allowing deeper and longer dives is slowly seeping into the local market, providing experienced divers access to the depths of the Great Barrier Reef and beyond.
The Rebreather - a closed-circuit breathing system that doesn't expel bubbles - was designed by the US Navy in the 1940s.The device allows divers to reach depths of at least 80m, compared with the 20 to 30m limit on regular dives.
Mike Ball Dive Expeditions embarked on one of the region's first public rebreathing expeditions recently, with divers exploring deep parts of Ribbon, Holmes, Bougainville and Osprey reefs.
Ship master Trevor Jackson said divers reached parts of the Reef that had never been explored before, with the deepest dive registered at 76m.
"The possibilities are virtually endless," he said.
"Just look at the Cairns region and all the reefs have been dived and they're spectacular but no one has dived past 40 or 50m.
"The world's our oyster and you could open up a whole new realm in terms of technical diving and Cairns diving." Prof Mitchell, who is the head of the University of Auckland's anaesthesiology department said the absence of bubblesallowed easier interactions with marine life.
"They're not scaring off the turtles or cod with bubbles," Mr Jackson said.