Built for Rebreather Divers by Rebreather Divers

Abyss and StingrayWe at Rebreathers Australia are a group of divers dedicated to desiging and building the Closed-Circuit Rebreather that we have been wanting to dive. As a result, we have brought to market the Stingray, designed for maximum transportability and for dives in the recreational depth range. In addition is the Stingray's larger sibling, the Abyss, offering longer dives, greater depths, and a larger gas supply.

Besides these ready-made units, we offer parts for the home-builder to incorporate into custom projects.


After years of diving with Semi-Closed Rebreathers, and a few Semi-to-Fully-Closed conversion projects, we realized that among our main design goals would be light weight and transportability.

The Stingray, completely loaded and ready to dive, weighs in at just 44 pounds. That's less than 2/3 the weight of the Semi-Closed Rebreather we had been diving, and even lighter compared to our converted rebreathers!


Both the Abyss and Stingray are fully enclosed in a smooth, streamlined case which measures just 7 3/4 inches from front to back.

Unlike most other rebreather designs, all cylinders, valves, regulators, counterlungs, and srubber canister are enclosed and protected, with a minimum of exposed hoses. We also place the valves and regulators at the top, so additional trim weights are not needed.


While the Abyss and Stingray are based on the same principles as Gordon Smith's KISS CCR, they were developed independently. We use a different method of O2 injection which allows for very easy adjustments of flow rate in the field.

This system produces a silent diving experience, eliminating the noise of solenoids and all of the electronics except for PO2 displays, while minimizing task loading for the diver.

The Abyss and Stingray CCR compared to electronically controlled units

Electronic CCRs require vigilant attention throughout a dive. They also require on-going maintenance (i.e. batteries, solenoids, wiring, etc.). One very well known Mark 15 trained diver said he was trained to monitor his unit every three minutes. With the Abyss or Stingray CCR, on the other hand, this task loading exercise is not required due to the passive injection of O2 which is set at just below the diver's O2 respiration rate. This keeps the PO2 very constant unless the diver does frequent ascents and descents throughout the dive, thus altering the volume in the counter lungs, in which case the O2 does need to be monitored more frequently. Otherwise, these units are much less task loading for the diver.

Another advantage is that, unlike with other CCRs, the diver can often almost forget he has it on his back for several reasons. One it is so hydrodynamically clean that it gives the diver a sensation he is free diving. No pull on the shoulders, no push on the lumbar spine, as it is so close to neutrally buoyant; silent and streamlined, thus the diver has a real sensation of free diving. The cylinders are mounted in a "valves up" position, which contributes greatly to the unit's balance. Opening and closing the valves while wearing the Stingray or Abyss is the same drill as shutting down an Open Circuit rig with manifolded doubles.

We have another Mark 15 Diver who just converted his unit using our system and he is very happy with the out come.