Rebreather Diving with the Poseidon: A Beginner's Guide

On regular scuba (open circuit), every breath you exhale goes out as bubbles — even though most of the oxygen in it was never used. A closed-circuit rebreather (CCR) recycles your breath instead: it scrubs out the carbon dioxide, adds back just the oxygen you've used, and lets you breathe the same gas again.

Why divers love rebreathers

• Almost silent and bubble-free — fish, turtles, and goliath grouper let you get much closer.
• Warm, moist breathing gas that's more comfortable on long dives.
• Very efficient — small cylinders can last for hours.
• Optimized gas mix at every depth, which can extend no-decompression time compared with air.
• Perfect for underwater photography and long wreck explorations.

How a rebreather works (the simple version)

• Breathing loop — you breathe in and out through a mouthpiece connected to counterlungs.
• Scrubber — a canister of absorbent material removes the CO₂ you exhale.
• Oxygen sensors — measure the oxygen level in the loop.
• Electronics — inject oxygen as needed to keep your breathing gas at the right level.
• Diluent and bailout — a second gas supply, plus an open-circuit bailout in case of a problem.

Why Poseidon?

Poseidon, a Swedish company with a long history in diving, designed its rebreathers to make CCR diving more approachable. Units like the Poseidon Se7en are known for highly automated electronics: the unit runs its own pre-dive checks, monitors itself during the dive, and gives clear alerts — taking a lot of the manual workload off the diver. Poseidon also offers recreational-focused configurations, which makes it a popular first rebreather for experienced open-circuit divers.

Is it right for me?

Rebreathers demand discipline. You'll need to follow checklists every time, maintain the unit carefully, and train specifically on your model. Typical prerequisites include Advanced Open Water, Nitrox certification, and a solid number of logged dives — exact requirements depend on the training agency and course.

Rebreathers on our boat

Our six-passenger boat has plenty of space for rebreathers, sidemount, and doubles, and our crew understands the needs of CCR divers. Planning a rebreather dive on the Gulf wrecks? Call us and we'll help set up the trip.