Dual CCR Diver course: two rebreathers on one diver, 4 days, 6 dives

Why take the Dual CCR Diver course?

Two rebreathers on one diver, both equal partners, breathed in turn. The plan for gas, sorb and oxygen is built for both units from the start of the dive. If one of them has a problem, the dive continues on the other in closed circuit. The course teaches to build the dive, the configuration and the team protocols around this arrangement.

Who is it for?

The Dual CCR course is for experienced CCR divers who plan long or deep dives. That means expedition and project diving, deep wall diving, long cave penetrations. It is also for divers who already own a rebreather and want to dive two. Owners of an S7 who want to dive it in its dual configuration belong here too.

How the Dual CCR course runs

• 4 days. At least 400 minutes of in-water training, all of it with both rebreathers on the diver for the whole dive. Students do not share units with each other or with the instructor. At least 120 minutes of confined water training to a maximum depth of 12 m. Six open water dives: four deeper than 15 m and two deeper than 30 m. No mandatory decompression stops on the first two open water dives. Classroom lectures, land drills and in-water work. Playa del Carmen or Puerto Aventuras area; transfer from Playa del Carmen included.
• Rate: $448 per training day in a group of two or more, $498 individually. Block I-CCR, for both units.
• Units: bring your two rebreathers, or rent from Cave Ha. GBM, S7, SF2, JJ or Fathom by the rental list; any two of these five. Volume discounts for unit plus course discussed during the order for the S7 and GBM from the dealer. S7 CCR, GBM CCR.

Equipment

Students must bring their own equipment per the list below or rent it from Cave Ha. Any rental equipment, including the S7 and GBM rebreather units, tanks, gases and sorb, is charged on actual usage. Students cover the cost of all gases and sorb used by the instructor, cenote entrance fees and certification card fees at $60 per card.

Cylinders per diver: 2 diluent/bailout cylinders AL80 DIN (sidemount or backmount doubles); 2 deco stage cylinders: 1 AL80 DIN and 1 AL40 DIN (oxygen).

Regulators and rigging

Regulators. Every regulator on the dive must be able to feed a rebreather: with two units in the water, every cylinder is a possible gas source for either unit. We recommend Swagelok QC6 connectors for diluent and QC4 for oxygen; standard 9/16 inflator connectors are acceptable.

• Diluent/bailout regulators, sidemount option: 2 regulator sets, each with DIN first stage, second stage, SPG, LP hose for the wing and drysuit, plus one LP hose with a QC6 (or 9/16) connector for the rebreather diluent port
• Diluent/bailout regulators, backmount doubles option: 1 technical regulator set with 2 DIN first stages, 2 second stages (long hose and necklace), SPG, LP hoses for the wing and drysuit, plus one LP hose with a QC6 (or 9/16) connector on each first stage for the rebreather diluent port
• 2 stage regulator sets for the deco cylinders, one of them oxygen-clean; each with an LP hose and connector for the rebreather: QC4 (or 9/16) on the oxygen regulator, QC6 (or 9/16) on the other
• 1 oxygen regulator for the S7 onboard oxygen supply: oxygen-clean first stage with LP hose and QC4 (or 9/16) connector. The GBM kit includes its oxygen regulator; the S7 kit does not, so one oxygen regulator per diver is needed for the S7
• Rigging: 2 sidemount rigging sets for the AL80 bailout cylinders if sidemount, 1 stage rigging set for the AL80 deco cylinder, 1 stage rigging set for the AL40

Exposure protection, harness and instruments

Exposure protection: 1 well-fitted drysuit with front-entry zipper, 2 pockets and 1 P-valve, plus 1 undergarment (Thinsulate 150 or equivalent); or 1 well-fitted wetsuit thick enough for 3-4 hours in 25 C water daily (5-7 mm preferred) plus tech shorts with 2 pockets; 1 thin neoprene hood; 1 pair of neoprene gloves, at least 1 mm.

Harness and buoyancy: 1 harness and wing suitable for the course configuration: for the S7 course, a sidemount harness or a backplate with doubles wing, able to carry the sidemount S7, 2 bailout cylinders and 2 stages; for Dual CCR, a harness and wing able to carry the chestmount GBM, the sidemount S7, 2 bailout cylinders and 2 stages.

Instruments and accessories: 1 bottom timer or deco computer, independent of the rebreather electronics; 1 wrist-mounted compass; 1 primary light, canister type or handheld type; 2 backup lights; 1 pair of Jet fins; 1 primary mask plus 1 backup mask; 1 small cutting device (for the webbing harness); 2 safety spools; 1 DSMB (closed type preferred); 1 wetnotes with pencil.

Rental: S7 mCCR TEC set $59, GBM mCCR TEC set $59, JJ eCCR set $79, Fathom MK 2.5 mCCR set $59, SF2 eCCR SM set $79 per day; Sofnolime $20 per kg.

Rules of the course

• Medical: every participant completes and signs the standard Diver Medical Participant Questionnaire before the activity. A YES answer to any question in its final section requires written approval from a physician before diving. Without it the guest does not dive.
• Liability: every participant signs the standard diving General Liability Release and Express Assumption of Risk before the activity. Without the signed form the guest does not dive.

Next step

• Dual CCR Cave Diver: two rebreathers in the cave, 5 days.
• Ocean Dual CCR DPV Trimix wall dives from shore to 150 m.