Pictures and text By Errol Harding

History of the ABYSS CCR

The ABYSS rebreather is a passive injection (adjustable to the divers O2 respiration rate) closed circuit rebreather. Its development began six years ago, using electronics to drive it in the beginning.

One day whilst diving a German O2 rebreather which had a constant flow of .9 Liter per minute, I suddenly realized I hadn't hit the O2 add button for over one hour. The over pressure relief valve had not exhausted, indicating my O2 respiration rate was matching that of the rebreather's set rate.

I spent some time considering how to incorporate this system in a mixed gas CCR. After experimenting with small jets and different orifices, I eventually found a needle valve to suit my requirements perfectly.

The next step was to streamline the system and to make it user friendly.

The Abyss can be stripped down in 20 seconds.

The CO2 canister can be recharged with fresh absorbent on site in minutes and reassembled to dive again.

I have dived the unit with nearly Two Liters of water in the exhaust bag (DSV mouth piece loose in the mouth to permit this leakage), and the unit still functioned perfectly.

In the last two years of diving this unit, I have never had to alter or re-adjust the set point of .9 Liters per minute.

The unit has a 15 micron filter to protect any contamination of the needle valve. Some may consider this to be overkill, but I would ask the reader to consider how many times the jets of the Dräger Dolphin SCR was found to be blocked by salt and the flow rate either stopped completely or was reduced.

The latest version (all carbon fiber) including cylinders can hold 3 Lt. (50 cubic Ft) cylinders and is extremely light. It was developed so I could spend a week away diving at my favorite dive site, Kangaroo Island, and not have to be concerned about refilling (20 hours of diving approx with a fill pressure of 4500psi).

Regards, Errol

Abyss at the OzTeK'03 Show

Abyss at OzTeK'03 Abyss at OzTeK'03

Here you see several prototypes and right is Mike Wescombe-Downs modeling the Abyss at OzTeK'03, with Errol to the left of picture. Everything on this rebreather has been hand made from tooling manufactured by Errol Harding. The cases are carbon fiber and an emphasis was placed on weight as you will see in subsequent pictures where Errol is now using Fiber Wrap cylinders

Abyss at OzTeK'03 Abyss at OzTeK'03

On the left is Mike modeling the "Abyss" from the front and right is a side view of the unit

Abyss at OzTeK'03 Abyss at OzTeK'03

Both left and right views of the scrubber canister complete with sensors and Gordon Smith's O2 gauges. Errol has used a number of different gauges on the Abyss, and seems to be very happy right now with the small "Kiss" style displays that Gordon makes for his Kiss Rebreathers.

Abyss at OzTeK'03 Abyss at OzTeK'03 Abyss at OzTeK'03 Abyss at OzTeK'03

These shots taken at OzTeK'03 while Errol was conducting an impromptu workshop on the floor outside the display area, everything has been carefully thought out and made to fit nicely inside the carbon fiber shell.

Abyss at OzTeK'03 Abyss at OzTeK'03

These pictures show some of the tank options you can use with the Abyss Rebreather. From left to right are 2.5 , 2.0, and 1.5 liter cylinders that will fit nicely inside the shell of the rebreather.

Abyss at OzTeK'03 Abyss at OzTeK'03

The above shots show a closer view of the CO2 scrubber and sensors mounted, plus Errol's own spiral hose design. In the front of the picture is a Dräger Ray hose. Errol was testing the Ray hose assembly as an option for the unit, however the spiral fluted hoses are easier to dry because they self drain and are a lot more flexible.

Abyss at OzTeK'03 Abyss at OzTeK'03

These shots outline the new breathing bags Errol is using on his latest design, which run the full length of the carbon fiber shell.

Abyss at OzTeK'03 Abyss at OzTeK'03 Abyss at OzTeK'03 Abyss at OzTeK'03 Abyss at OzTeK'03

All of the above pictures were taken of Errol on his Abyss rebreather diving the President Coolidge in Micronesia

The Abyss Closed Circuit Rebreather is now availablefor purchase. See our Ordering and Contacts pages for details.