Purpose

GUE's Rebreather Diver course is designed to 1) educate individuals in basic rebreather technologies and 2) cultivate diver proficiency in the use of Halcyon's semi-closed-circuit technology. The course assumes that divers are not experienced in the use of rebreather technology but are very capable open-circuit divers.

Prerequisites

1. Must meet GUE General Course Prerequisites as outlined in Section 1.6
2. Must be a minimum of 21 years of age
3. Must have passed GUE Tech 2 (or equivalent)
4. Must have at least 300 scuba dives beyond open-water qualification. Fifty must have been in doubles, with twenty-five involving stage decompression.

Duration

The Rebreather class is normally conducted over a five-day period. It involves a minimum of forty hours of instruction, encompassing both classroom and in-water work.

Course Limits

1. General Training Limits as outlined in Section 1.4
2. Student-to-instructor ratio is not to exceed 3:1 during any in-water training
3. Maximum depth 100 feet/30 meters

Course Content

The GUE Rebreather course involves a minimum of forty hours of instruction designed to ensure a working knowledge of rebreather diving, failures and life-saving solutions. Course requirements include a minimum of twelve hours of academics and at least eight open-water dives.

Required Training Materials

1. Doing it Right: The Fundamentals of Better Diving. Jarrod Jablonski, GUE, 2001, High Springs, Florida.
2. Getting Clear on the Basics: The Fundamentals of Technical Diving. Jarrod Jablonski, GUE, 2001, High Springs, Florida.
3. Recommended rebreather training materials.

Academic Topics

1. Purpose
• Purpose
• Common components of the Halcyon RB80 and how they function
• Inherent risks of rebreathers
• Introduction to the Halcyon rebreather
• Halcyon rebreather alarms and warnings
• The physics behind a Halcyon rebreather
• Configuration
• Halcyon rebreather physical design
• Problem recognition and management
• The importance of instinctive physiological monitoring
• Pre-dive planning
• Diving the Halcyon rebreather
• Post-dive procedures
• Need for continuing education and skill reinforcement

Land Drills & Topics

1. Flow-checks
2. Manifold failures
3. Gas-addition failures
4. Gas-sharing
5. Rebreather functions

Required Dive Skills & Drills

1. All skills and drills as outlined in General Diving Skills, Section 1.5.
2. Must be able to swim at least 500 yards/450 meters in under fourteen minutes without stopping. This test should be conducted in a swimsuit and, where necessary, appropriate thermal protection.
3. Must be able to swim a distance of at least 20 yards/18 meters on a breath hold
4. An understanding of diving limitations.
5. Skill required to manage gas failures, including valve manipulation, gas-sharing, and regulator switching as appropriate.
6. Demonstrate the ability to deploy a lift bag/surface-marker buoy in under two minutes while hovering stationary. Participants should not vary in depth more than 5 feet/1.5 meters.
7. Demonstrate the ability to recognize, evaluate and correct water floods, and then discharge excess water.
8. Demonstrate the ability to diagnose and correctly respond to simulated rebreather problems.
9. Gas-sharing scenarios to include breath-hold management for gas-sharing for at least 200 feet/60 meters.
10. Demonstrate effective valve-management by switching regulators, shutting down a valve in under fifteen seconds and returning the valve to the open position again in under fifteen seconds.
11. Demonstrate proficiency in removing/attaching stage and/or dempression bottles while hovering horizontal. Trainees must be capable of removing, replacing and plugging in a deco bottle in under ninety seconds.
12. Demonstrate the ability to comfortably switch gases using the gas-addition manifold while maintaining good trim and neutral bouyancy.
13. Demonstrate proficiency in safe diving procedures, including assembly, vacuum and pressure test, pre-dive preparations, pre-dive vacuum test, flow check, in-water activity, and post-dive assessment and breakdown.
14. Comfortably swim for at least 50 feet/15 meters without a mask while diving, breathing on semi-closed circuit.
15. Demonstrate the ability to safely switch between semi-closed circuit and open circuit, i.e. flow check.
16. Efficiently and comfortably demonstrate how to donate gas to an out-of-gas diver in multiple gas-sharing episodes from semi-closed circuit, with one or more experiences to include a distance of at least 30 feet/9 meters.
17. Be able to comfortably demonstrate use, manipulation and failure of the gas-addition system.
18. Demonstate awareness of a team member's rebreather function and a concern for safety, responding quickly to visual cues and needs during diving and failures.
19. Demonstrate reasonable proficiency with use of the rebreather during ascents, descents and diving.
20. Demonstrate good buoyancy and trim, i.e. appropriate reference maximum of 20 degrees off horizontal while remaining whithing 3 feet/1 meter of a target depth. Frequency of buoyancy variation as well as general diver control remain important evaluation criteria.

Equipment Requirements

Each student should have, and be familiar with, all of the following required equipment.

1. Rebreather: Halcyon semi-closed circuit rebreather
2. Tanks/Cylinders: Students are required to use dual tanks/cylinders connected with a dual outlet isolator manifold, which allows for the use of two first-stages. The double cylinders must be accessible by both the rebreather and the open circuit regulators. Two aluminum cylinders of 30 cubic feet/840 liters or greater are required for deco gases.
3. Regulators: Two first-stages, each supplying a single second-stage. One of the second-stages must be on a 7 foot/2 meter hose. One of the first-stages must supply a pressure gauge and provide inflation for a dry suit (where applicable). One first-stage regulator for shallow decompression gas and one first-stage regulator for travel/decompression gas; each one is to supply a single second-stage and a single pressure gauge.
4. Backplate System: A rigid and flat platform, of metal construction with minimal padding, held to a diver by one continuous piece of nylon webbing. This webbing should be adjustable through the plate and should use a buckle to secure the system at the waist. A crotch strap attached to the lower end of this platform and looped through the waistband would prevent the system from riding up a diver's back. A knife should be secured to the waist on the left webbing tab. This webbing should support five D-rings; the first should be placed at the left hip, the second should be placed in line with a diver's right collarbone, the third should be placed in line with the diver's left collarbone, the fourth and fifth should be affixed to the crotch strap to use while scootering or towing/stowing gear. The harness below the diver's arms should have small restrictive bands to allow for the placement of reserve light powered by three in-line c-cell batteries (where necessary). The system should retain a minimalist approach with no unnecessary components.
5. Buoyancy Compensation Device: A diver's buoyancy compensation device should be back-mounted and minimalist in nature. It should come free of extraneous strings, tabs or other material. There should be no restrictive bands or "bungee" of any sort affixed to the buoyancy cell. In addition, diver lift should not exceed 80lbs. Wing size and shape should be appropriate to the cylinder size(s) employed for training.
6. At least one time/depth-measuring device
7. Decompression tables
8. Mask and fins: Mask should be low volume; fins should be rigid, non-split
9. At least one cutting device
10. Wet Notes
11. One spool with 100 feet/30 meters of line per diver
12. One primary reel per team, with a minimum of 300 feet/90 meters of line
13. One primary light: A primary light should be minimalist in design; its power source should consist of a rechargeable battery pack residing in a canister powering an external light head via a light cord. Primary lights should produce the equivalent output of 50 watt halogen/10 watt HID lighting or greater.
14. Two reserve lights: Reserve lights should be non-rechargeable with a minimum of protrusions and a single attachment at its rear. The light should be activated by twisting the front bezel towards the body, deactivated by turning it away from the body.
15. Exposure suit appropriate for the duration of exposure
16. At least one surface marker buoy per diver
17. Divers breathing Helium mixtures and utilizing a dry suit must have a separate (from the back gas) dry suit inflation source, such as an Argon/air bottle. Divers may not inflate the dry suit from the back gas.

Note: Prior to the commencement of class, students should consult with a GUE representative to verify equipment requirements. Whether or not a piece of equipment fulfills GUE's equipment requirement remains at the discretion of GUE and its instructor representatives. Participants are responsible for providing all equipment or for making provisions to secure all necessary equipment before the start of the course. In general, it is better for the student to learn while using his or her own equipment. However, students should exercise caution before purchasing new equipment to avoid acquiring substandard equipment. Please contact a GUE representative prior to making any purchases. Information about recommended equipment can be obtained from the equipment considerations section of GUE's web site.