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SF2 Rebreather Training

with SF2 Rebreather Instructor Tom McCarthy

SF2 Rebreather instructor Tom McCarthy is proud to be one of a select group of SF2 Rebreather Instructors located in the United States and more specifically, the only authorized SF2 instructor in New York and New Jersey. We can custom tailor your training schedule and work alongside you to master your sidemount or backmount SF2 Rebreather. Please feel free to contact us for any questions you may have regarding SF2 Rebreather instruction.


IANTD Closed Circuit Rebreather Diver (CCR)

Course Standards

Who may teach the course: A Rebreather instructor may teach the course provided they are an instructor on the specific Rebreather being taught in the course. The instructor may use any other CCR they are diver qualified in addition to being an instructor on the one being taught in the class. The instructor may not teach a rebreather they are not qualified on as an instructor. For instance, a Sentinel Instructor may not teach an O2ptima Diver class unless they are also an O2ptima Instructor.  An instructor may use any rebreather on which they are diver-qualified to teach the class.

A. Purpose

1. This Program is designed to train competent divers in the safer use and technology of CCR for dives requiring up to 15 minutes of decompression. It is also especially useful to train divers who wish to dive up to 160 fsw (48 msw) if using diluent with helium or 140 fsw (42 msw) if using air as a diluent. The training requirements here-in are IANTD minimums. Other manufacturer’s requirements MAY APPLY for specific Rebreathers so consult IANTD specific CCR course materials and manufacturers literature prior to teaching.

B. Prerequisites

1. Must be an IANTD Advanced EANx or Advanced Recreational Trimix Diver or equivalent. (May be taken in conjunction.)

2. Must be a minimum of 17 years of age.

C. Program Content

1. All lectures completed with IANTD Course-specific Slides pertaining to the theory in the IANTD CCR-specific Diver Student Kit.

2. This Program must include a confined water session, followed by 6 OW dives with a minimum of 500 minutes of in-water training time using the specific Rebreather on which they are being trained. If qualified Recreational CCR diver, the total in-water training time is decreased to 400 minutes and the dives are decreased to a minimum of four (4) OW dives.

3. Students must complete the text with the units on which they wish to be qualified.

4. Students must pass the specific CCR test with a minimum score of 80%.

5. On a minimum of four (4) dives the student must carry a single stage cylinder or other bailout gas adequate to safely ascend.

6. Three (3) dives must be a minimum of or deeper than 50 fsw (15 msw) of which one (1) of these three (3) dives must be a

minimum of 100 fsw (30 msw).

7. To qualify from one Closed Circuit Rebreather to another Closed Circuit Rebreather, a diver must have 12 CCR dives of which

one (1) must have been within 45 days of the program on the new CCR and must complete a minimum of 200 minutes of in-

water training with at least two (2) OW dives.

8. To qualify from a Semi-Closed Circuit Rebreather to a Closed Circuit Rebreather, a diver with 20 or more SCR dives must complete a minimum of 400 minutes of in-water training in a combination of confined water and OW environments, with at least 6 OW dives. Divers with less than 20 SCR hours must complete the entire course.

D. Text & Equipment Requirements

1. IANTD CCR-specific Diver Student Kit, to include IANTD Tek CCR Manual, operations manual, IANTD C-3401 “S” Drill Sheet, IANTD Constant PO2 Tables, IANTD Bailout Table and balance TBA.

2. Approved specific Rebreather suitable for the training exposure. The instructor should notify the student that if the student does not take possession of, or have access to a rebreather within three (3) months of completion of training it is recommended the student take a refresher course for there own benefit. This should include review of operations of that rebreather along with a confined water and as many dives as is necessary for the instructor to feel the student is proficient at the survival skills.

3. Instructors must have (students are recommended to have) the IANTD Waterproof CCR Skills sheets C-3400 1&2 on all confined and OW dives.

E. Program Limits

1. This program must include a confined water session(s). In lieu of confined water the instructor may opt to do a skills development dive to a depth no greater than 60 fsw (18 msw) provided required decompressions stops are not required.

2. There may be no more than four (4) students per Instructor, except for when a CCR qualified Dive Supervisor is used at which time the ratio may be increased to 6 students.

3. Mandatory decompression stops are limited to a maximum of 15 minutes.

4. No dives may be conducted to depths greater than 160 fsw (48 msw) in which case the END will not exceed 80 fsw (24 msw) if

using diluent with helium or 140 fsw (42 msw) if using air as a diluent.

5. The set point of the CCR must not exceed 1.3 ATA, except for failed open solenoid drills. At safety or required deco stops the

set point may be increased to 1.4 ATA. At 20 fsw (6 msw) a flush to 1.6 may be used to check cell performance.

6. The oxygen partial pressure of the bailout gas may not exceed 1.6 ATA at the MOD of the dive.

7. All dives must be completed within the IANTD oxygen CNS% limits.

8. All appropriate safety or required decompression stops must be performed.

9. Only one (1) stage / decompression bottle may be carried or used on any dive.

10. Diluent PO2 shall be not greater than 1.1.

F. Water Skills Development

1. (RB) Divers on CCR complete the IANTD “S” drill chart C-3401 prior to all water sessions.

2. Prior to dives, students must use match gas turn points based on oxygen metabolism.

3. Pre-dive checks including Pre-dive Breathe.

4. Switch to low set point for descent and monitor the PO2 to ensure it remains within the planned PO2 range.

5. Switch to planned set point once the diver is at the planned dive depth or set point change depth.

6. In water leak and buddy leak check. If conditions prohibit this after entry this then immediately upon arrival at a stable depth.

Where practical this may be accomplished between just below the surface to 20 fsw (6 msw) deep.

7. Descend and insure gas addition is made.

8. Open Circuit bailout (static and dynamic drills, including at least two (2) OC ascents to approximately 20 fsw (6 msw). On one

(1) dive ascend a minimum of 30 fsw (9 msw) and record time it took and amount of gas used. Post dive, based on this drill,

plan the amount of total bail-out gas that would have been needed in a real situation.

9. PO2 gauge monitoring to be done no more frequently that once a minute and no less often than once every four (4) minutes

10. Perform BOOM Scenario where diver see’s massive bubbles suddenly and checks and corrects or performs safe procedure

11. Become proficient in these propulsion techniques: modified flutter, modified frog, modified dolphin, standard shuffle kicks.

12. Buoyancy and trim on the bottom during ascent and at safety or required stops.

13. Hyperoxia due to Solenoid stuck in open position. (Reset to a high PO2 set point maintain at a value less than this by valve manipulation.) On one (1) dive do this for at least 10 minutes. 

14. Dive the unit in full manual mode for one (1) dive.

15. Optimum Loop Volume.

16. Emphasis is to be made that once a bailout has been done the student should not go back on the unit if they are unsure of the

cause of the problem or how to correct it.

17. Carry additional bailout on all dives (limited to a single stage cylinder).

18. Simulate manual gas control with valve shutdowns.

19. Deploy lift bag, and repeat at least three (3) times during the Program.

20. Swim a distance of at least 75 feet (23 meters) without wearing a mask.

21. Practice removing and replacing a stage cylinder, both at rest and while swimming.

22. Post dive briefing.

23. On CCR with the ability to upload and / or down load software the student must be taught to do so.

!!! At least two (2) times on each dive, Instructor is to signal to student(s) that they have an emergency. On the last two (2) dives, present the following situations. The student is to perform appropriate actions and write down the suspected problem. At least once per dive perform complex (multi-part) scenarios such as Hypoxia or Hyperoxia drill for donor while gas sharing by handing bailout cylinder or other bailout mechanism to an out-of-gas diver and ascend.

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