Online Review, on the RebreatherWorld Forums

Dan Nafe, principal designer of the Nautilus Dive Planner and founder of, tried the Stingray Closed Circuit Rebreather while diving for a couple of days with Curt Harpold in Florida.

Dan wites:

This spring I trained Curt as an Inspiration diver and got to use his Stingray.

Let me say this: This is the finest MCCR I have ever used. This little machine "handles" ("swims" ?) like a dream. It is hydrodynamically very "clean" and compact.

The best part of this MCCR is that the center of buoyancy and the center of gravity are very close together, making it very stable about the pitch axis.

The unit's small size gives the diver a great deal of agility about all axis and the flat bottom makes it easy to stow aboard a dive boat.

The cylinders are mounted in the case in a "valves up" position. This contributes greatly to weight and balance solution. Opening and closing the valves while wearing the Stingray is just like shutdown drills with manifolded doubles.

The case is very rugged with no sharp edges and no delicate items that would break off easily.

Due to the Stingray's homebuilt origins, all of the parts look to be very field serviceable. It looks like a trip to the local plumbing supply store would yield all of the parts necessary to do a complete overhaul.

The spirally-corrugated breathing hoses are nice and the scrubber canister is very easy to clean and inspect. (I would consider adding a "scrim" to each end of the scrubber to get some of that electro-static protection against dust Martin talks about...)

Diving in South Florida on the regular cattle boats I was able to wear 4 pounds of lead (about 2 kilograms) on a conventional belt with a 1mm wetsuit and a 3mm hooded vest. NO TRIM WEIGHTS NEEDED! When your ballast is just right (in warm water, with a thin suit, etc.), the BC is really not used much, if at all. (Yes, I am an Alpinist at heart.)

Because the unit feels like a small (but wide) scuba cylinder, you could use a more "recreational" BC. (It feels like the old Twin-45s on your back)

The unit employs a Jetsam mouthpiece and electronics. Some Drager fittings are used on the counterlungs. Excellent choices.


If you are not mindful of keeping minimum loop volume on ascent, the counter lungs crawl out of the case. It looks kind of goofy but is no problem.

As with any MCCR, the system is depth limited at the point where the intermediate pressure of the oxygen first stage and the ambient pressure achieve unity.

It takes a few dives to get your nominal oxygen flow rate to match your metabolic rate (as with any MCCR).

Decompression must be calculated conservatively, as you would with any MCCR.

Gas capacity: The unit is set up for 13 cubic foot aluminum cylinders, so sharing diluent with someone else is really out of the question. Carry a bail out cylinder!

Acquisition: The challenge will be to get the units delivered at a reasonable cost and within a reasonable time span.

My summary:

The Stingray is a great little machine! It will not replace my Inspiration, but is a great addition to my quiver of RBs. Of all of the systems I have used (Inspiration, Megladon, KISSes, Dragers, Prism and Mk15) this is the most compact and "fun" to swim with in the water. The design is elegant and workmanlike at the same time.

A Stingray owner could add all sorts of pneumatics and electronics and increase the depth and gas capacity of the machine, but why ruin a great machine? (Kind of like adding a roof luggage rack and cargo trailer to a Porsche 911)