Wednesday, May 30, 2007

Technical Diving International – Drager Dolphin Semi-Closed Circuit Rebreather Diver Course

TDI – Semi-Closed Circuit Rebreather Diver Course, Unit Specific- DOLPHIN

Drager Dolphin Semi-Closed Rebreather course required dives to be held at Crescent Lake, Oregon on August 4 and 5, and August 25 and 26, 2007.


This is the entry-level certification course for recreational divers wishing to utilize one of the following Semi-closed circuit Rebreathers; Dolphin. The objective of this course is to train recreational divers in the benefits, hazards, and proper procedures for using SCR Rebreathers.

Required Equipment

The following equipment is required for each student:

1. Drager Dolphin Rebreather.
2. Integrated PO2 monitoring device for inhaled PO2.
3. Mask and fins.
4. Exposure suit appropriate for the open water environment.
5. Access to oxygen analyzer.
6. Appropriate weight.
7. Bailout cylinder (minimum size 3L / twelve (12) cu. ft.)
8. Flow meter.

The Rebreather Manual and the manufactures’ manual are mandatory for use during this course.

The following topics must be covered during this course:

1. History and Evolution of Rebreathers.
2. Comparison of Open Circuit, Closed Circuit, and Semi-closed Circuit.
3. Practical Mechanics of the System

A. Assembly and disassembly of the Rebreather.
B. Layout and design.
C. Scrubber recharge.
D. System maintenance.
E. Breathing loop decontamination procedures.
4. Review of nitrox
A. Dalton’s Law (triangle)
B. Optimum nitrox mix
C. Oxygen Tracking
D. Gas preparation
E. Dive planning examples
5. Gas physiology
A. Oxygen toxicity.
B. Hyperoxia.
C. Hypoxia.
D. Asphyxia
E. Hypercapnia
F. Nitrogen absorption.
G. CO2 toxicity.
H. Gas consumption.
i. Cylinder sizes
ii. Depth and workload
6. Formula work / metabolic consumption
A. 02 metabolizing calculations.
B. Inspired 02 calculations (Rebreather Equation).
C. Equivalent air depth.
7. Dive Tables
A. Inspired 02 table.
B. Equivalent air depth.
8. Dive Computers
A. Mix adjustable.
B. 02 integrated.
C. P02 monitoring devices
9. Problem Solving
A. Canister flooding
B. Mouthpiece loss
C. Scrubber exhaustion
D. Battery or sensor loss
E. Breathing Bag rupture
F. Open circuit bailout system
i. On board gas
ii. Off board gas
G. Hyperoxia scenario
H. Hypoxia scenario
I. hypercapnia scenario
J. Post problem maintenance of equipment
10. Dive Planning
A. Operational Planning
i. Gas requirements.
ii. Oxygen limitations.
iii. Nitrogen limitations.

Required Skill Performance and Graduation Requirements:

The dive depth shall not exceed one point six (1.6 ATM) P02.

The following skills must be completed by the student during open water dives:

1. Properly analyze gas mixture.
2. Perform all pre dive checks (positive, negative, flow rate, by-pass regulator operation, relief valve pressure) a minimum of six (6) times.
3. Demonstrate a leak check and repair scenario.
4. Not required for the Dolphin.
5. Properly packing a scrubber canister a minimum of two (2) times (if using the ExtendAir cartridge one packing must be with granular material).
6. Properly execute set-up and breakdown a minimum of four (4) times for Draeger rebreathers.
7. Demonstrate adequate pre-dive planning.
A. Limits based on system performance.
B. Limits based upon oxygen exposures at planned depth with mix.
C. Limits based upon nitrogen absorption at planned depth with mix.
8. Properly execute the planned dives within all pre-determined limits.
9. Properly execute a recovery from a system failure and switch to bail-out stationary a minimum of two (2) times.
10. Properly execute a recovery from a system failure and switch to bail-out hovering a minimum of two (2) times, one of the bail-out scenarios the diver must switch to open circuit and complete dive and safety stop on open circuit (direct ascent must begin when diver switches to open circuit, this scenario should be conducted no deeper than 60 fsw / 20 meters).
11. Properly demonstrate hose clearing technique after each bail-out scenario.
12. Not required on a Dolphin.
13. Proper PO2 monitoring on all dives (if unit is equipped with P02 monitoring device).
14. Properly execute a mask clearing exercise with emphasis on minimal gas loss.
15. Safely and properly execute a buddy out of air scenario, it is preferable the buddy is on a SCR unit also.
16. Diver will demonstrate actual safety stops at pre-determined depths.
17. Properly execute cleaning and maintenance of the Rebreather, including breathing loop decontamination.

Course Structure and Duration

Open Water Execution:

A minimum of four (4) dives with a minimum of one hundred (100) accumulated minutes for the Drager units.

Course Structure:

1. Structure of the course is according to the number of students participating and their skill level.


1. The minimum number of classroom and briefing hours is six (6).

In order to complete this course, students must:

1. Satisfactorily complete the TDI Rebreather Course written examination.
2. Complete all open water requirements safely and efficiently.
3. Demonstrate mature, sound judgment concerning dive planning and execution.

Qualifications of Graduates

Upon successful completion of this course, graduates may engage in no decompression diving activities utilizing the Dolphin to a maximum depth of forty (40) msw / one hundred thirty (130) feet, without decompression utilizing nitrox mixes not exceeding their level of certification.

Please email if you are interested or want additional information.

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