A Working Reg: the Poseidon Jetstream

Jetstream and Odin
Poseidon is a recognized name in the world of diving, particularly for technical and commercial divers in cold climates. Today I’ll be reviewing the Jetstream (currently at Mk.3) series of regulators and and the Odin first stage. Why that combo? The Jetstream Mk.3 is still is service and production by Poseidon, and widely available. The Odin was the last generation of first stage used with these regs (the Xstream is the current standard), but is still available from many sources both used and new. I purchased mine on eBay.com from an ex-diver in the Great Lakes region, and here’s what I’ve found:

Overview:
The Poseidon Jetstream Mk.3 regulator set (second stage and octo) and Odin first stage are simple and rugged in design. The regulators have simple controls: a large rubberized purge button, and a simple “-/+” sliding switch for air flow, and can be used with either side up. The Odin first stage has lots of ports: 2 HP and 4 LP, divided evenly on each side of the first stage. The Odin, like the newer Xstream, is DIN standard; it requires an adapter (usually comes with the first stage) to be used on yolk standard valves. The Odin is rated to 300 Bar (4351 psi for those not caught up to the metric system), on both DIN and yolk.

Operation:
The system is a downstream one, the second stage regulator requires pressure to seal. This can be a bit surprising the first time you open your tank valve and a gust of air bursts out. It’s perfectly normal though. When opening your valve for these regs, don’t go slow! The air flow can be a bit hard to get used to at first. “-” provides minimal flow, and I mean minimal. “+” will give you all the air. At once. Controlling your respiration (but not skip breathing) is key with these regs. The regs come into their own at depth, providing the smoothest respiration I’ve had at 30m or deeper to date. They’re also cold water rated (Poseidon is a Swedish company after all), and work just as well in frigid lake water in the Okanagan as they do in the warm waters of Oahu. These regs are LOUD though, so you, and your dive buddy, and the local marine life will all know that you are breathing.

The Odin first stage is, well, easy. It gives you lots of ports to plug in your everything. The adaptor is easy to install as well, allowing you to use both DIN and yolk tank valves. It also has an in built system to help prevent foreign objects from getting into it, which is handy for shore divers.

Maintenance:
Maintenance is simple. For the first stage, make sure you use your cap to keep additional moisture out of the first stage. Rinse the whole system thoroughly with freshwater after use, and rinse the insides of the regulators out after use. Store them properly in a case (once dry) or from a suspension system that doesn’t place strain on the hose connection points. Professional maintenance can be tricky, depending on where you’re located. In Canada, the northern parts of the USA and Europe, trained repair staff are fairly easy to find. Otherwise, you’ll probably have find a commercial diving company and ask them or find out where their kit gets maintained. Fortunately, breakdowns and failures are uncommon with these regs, and your daily care should keep them in good working order.

Final Say:
These are sturdy, reliable regulators suitable for both recreational and professional diving at all levels. They have a few quirks owing to design, but none that aren’t easily surmounted by regular use. Like any other piece of life support equipment, maintenance is important; if you purchase your set second hand (as I did), ensure that they come with proof of maintenance in the last six months, or check that you have a facility capable of maintenance near by and have them checked prior to diving. Sweden makes good diving gear!

About the author

Graeme Barber is a professional diver, qualified as a PADI and SDI Divemaster, DCBC 40m Unrestricted Commercial Scuba Diver, 30m Restricted Surface Supply diver, and CAUS Scientific Diver Lv.2. In addition to being the head of Cold Water Diver, he's a full time student working on a degree in Archaeology.