
S7 rebreather: the sidemount unit from the authorized dealer and the S7 CCR Nitrox / Helitrox course
The S7 rebreather is a compact manual sidemount unit (mCCR) with a 1.9 kg scrubber. Its configurations run from recreational diving to cave diving and Dual CCR. Approved instructors sell the unit, and Cave Ha is an authorized dealer that supplies it to order. The first course on it is CCR Nitrox / Helitrox Diver, 5 days. Divers certified on another rebreather cross over in 3 days.
The unit
- S7 sidemount rebreather, basic configuration, delivery in Mexico: $6,990. Cave Ha supplies it to order as the authorized dealer; you agree the configuration during the order. Delivery in Europe or elsewhere: quoted during the order.
- Volume discounts for unit plus course discussed during the order.
- Service and support: by the manufacturer’s policy, every approved S7 instructor services the unit. Your instructor at Cave Ha is one of them.
Why take the S7 CCR Nitrox / Helitrox Diver course?
The S7 rebreather course aims at a smooth transition from open circuit to closed circuit. It builds the essential skills of rebreather management, maintenance and operating protocols in a structured, supportive environment. Safety and confidence come first. The result is a solid foundation for technical and cave diving on a CCR. The course is also the prerequisite for all further CCR training.
Who is it for?
The S7 rebreather course is for divers who want to dive a closed-circuit rebreather. They need a technical configuration and the related skills. The course is also for owners of a new S7. Divers already certified on another unit take the S7 crossover: 3 days on the same program.
What will I learn?
- A competent and comfortable CCR diver with solid personal and team skills
- Rebreather preparation, function, dive operation, and what to do in case of failures
- Bailout to open circuit, including the ascent protocol
- Planning of recreational dives on a CCR: gas management, scrubber endurance, oxygen toxicity management, minimum decompression ascents
How the course runs
- 5 days. At least 8 in-water sessions and at least 480 minutes of training, confined water and open water. You train on the S7 rebreather you will dive.
- Classroom lectures, land drills and in-water work. Playa del Carmen or Puerto Aventuras area, transfer from Playa del Carmen included.
- Crossover from another rebreather: 3 days. At least one confined water session of 60 minutes, at least two open water sessions, 200 minutes in total.
- Rate: $398 per training day in a group of two or more, $448 individually.
- Included: professional Advanced Technical Dual CCR Cave Diving instructor, hotel pickup and drop-off in Playa del Carmen, doubles or sidemount tanks with EAN32, weights, and the final examination
- Not included: Students must bring their own tech/cave level diving gear (requirements will be provided) or rent it, Additional sets of Doubles or Sidemount tanks with EAN32, Stages, Drysuit tanks, Sofnolime, Oxygen, Trimix or Argon fills for both students and Instructor / DPV rental for students and Instructor / Cenote entry fee / Any Rental equipment will be charged accordingly, Foto/Video service, Diving insurance, Camera fee (depend on Cenote policy), Fuel or boat surcharges for remote locations out of Playa del Carmen and Puerto Aventuras areas (as per student request), eLearning materials or/and printed manuals, Certification fee ($60 per card), Tips for instructor
Applicants must
- Be qualified in Advanced Open Water Diver and Nitrox or equivalent
- Be a minimum of 18 years of age, or 15 with a parent or guardian authorization
- Be physically and mentally fit; obtain a physician’s prior written authorization for prescription drugs or any medical condition that may pose a risk while diving
- Be experienced with technical diving configuration and related skills: Basic 5, V-Drill, S-Drill, 6 propulsion techniques including back kicks and helicopter turn, perfect buoyancy, trim no more than 20 degrees out of neutral (see Intro to Tech / Essentials + Nitrox, link /cave-diving/intro-to-tech-essentials-basic-nitrox-course/)
- Have a minimum of 100 logged dives
Equipment for the S7 rebreather course
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, instruments and harness
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.
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.
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.
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.

Your instructor: Alexander Vronsky
IANTD and IDF Instructor Trainer. IDF Course Director.
Alexander trains cave and technical divers, rebreather divers and the instructors who teach them, year-round, in the cenotes and caves of the Riviera Maya, home to the longest underwater cave systems in the world.
Cave and technical instructor trainer: Cavern to Technical Cave, Technical to Master Deep. CCR instructor: Dual CCR and Dual CCR Cave; GBM CCR from Nitrox to Trimix 100; S7 CCR from Nitrox to Helitrox; CCR Cave, CCR Technical Cave and CCR Expedition Cave on GBM, S7, SF2, JJ and Fathom. Authorized dealer for S7 and GBM rebreathers. TDI technical instructor.
GUE Member. GUE Cave 2, Cave DPV, Cave CCR, CCR 2, Tec 3.
Elected representative of CREER, the regional cave diving committee of Quintana Roo (Comité Regional de Espeleobuceo, Ecología y Regulación).
Alexander teaches the cave and technical courses himself, in English and Russian.
An engineer by training, Alexander ran large-scale technical and broadcast operations in telecom and for the Olympic Games before diving became his profession. That experience shows in how every course here is planned and run.