GUE Doubles Course
Purpose
GUE’s Doubles course is designed to prepare divers for diving a double tank/cylinder configuration using
proper equipment and techniques.
In this class, students will be trained in the use of double tanks/cylinders and in the potential failure
problems associated with them.
Prerequisites
1. Must meet GUE general course prerequisites as outlined in section 1.6
2. Must be a minimum of sixteen years of age.
3. Must be a certified open-water diver from a recognized training agency
Duration
The GUE Doubles Course must be conducted over at least two days, encompassing both classroom and inwater
work. Course requirements include a minimum of 6 hours of academics & land drills and a minimum
of four in-water sessions; at least two of these dives must include a depth of at least 40ft/12m. Course time
should total at least 16 hours encompassing classroom, land drills 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 6:1 during land drill or surface exercises, but cannot
exceed 3:1 during any in-water training, and should be adjusted downward to account for bad
conditions and/or poor visibility.
3. Maximum depth 60 feet/18 meters
4. No decompression
5. No overhead environment diving
Course Content
Combining lecture and in-water sessions, this course focuses on cultivating the basic skills required. The
GUE Doubles course is focused on increasing proficiency with double tank configuration, through proper
control of the buoyancy, trim, propulsion, teamwork and other GUE principles.
Training Materials
• GUE Doubles Presentation
Academic Topics
1. Class Overview
2. GUE Introduction
3. Double Tank Introduction
4. Developing Diver Capacity
5. Tanks/Cylinders and bands
6. Manifolds
7. Regulators, depth gauges, pressure gauges and hose routing
8. Buoyancy and Trim
9. Skills overview
10. Pre dive sequence
11. Situational Awareness
Land Drills
1. Gas analysis and labeling
2. Valve Drill
3. S-Drill
4. Valve failure procedures
5. SMB deployment (review)
6. Backup light deployment (review)
7. Pre-dive sequence
8. Team positioning
9. Communication
Required Dive Skills and Drills
1. Demonstrate proficiency in safe diving techniques; this would include pre-dive preparations, inwater
activity and post-dive assessment
2. Must be able to swim at least 300 yards/275 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 16 yards/15 meters on a breath hold
4. Demonstrate proficiency with required course equipment and an understanding of the GUE
equipment configuration.
5. Demonstrate good buoyancy and trim, i.e. approximate reference maximum 30 degrees off
horizontal while remaining within 5ft/1.5m of the target depth. Frequency of buoyancy variation
and the divers control of their buoyancy and trim are important evaluation criteria
6. Efficiently and comfortably demonstrate how to donate gas to an out-of-gas diver.
7. Efficiently and comfortably demonstrate how to donate gas to an out-of-gas diver, followed by an
ascent to the surface, utilizing minimum decompression.
8. Demonstrate proficiency in executing a valve drill with double tanks.
9. Demonstrate safe ascent and descent procedures.
10. Demonstrate proficiency in the ability to deploy a surface marker while using a spool.
11. Comfortably demonstrate at least three propulsion techniques that would be appropriate in delicate
and/or silty environments.
12. Demonstrate proficiency with effective valve management by first sharing gas with a tem member
(as a receiver), then shutting down a valve and returning it to the open position.
13. Demonstrate a safe and responsible demeanor throughout all training.
14. Demonstrate proficiency in underwater communication.
15. Demonstrate proficiency with a primary light by using it during all skills except SMB
deployment.*
16. Demonstrate efficient deployment and stowage of a backup light.*
17. Demonstrate an efficient valve drill with double tanks.*
18. Comfortably demonstrate an efficient backwards kick.*
19. Demonstrate good buoyancy and trim, i.e. approximate reference maximum 20 degrees off
horizontal while remaining within 3ft/1m of the target depth. Frequency of buoyancy variation and
the divers control of their buoyancy and trim are important evaluation criteria.*
*Skills 12-17 apply to students wishing to use the GUE Doubles class to upgrade a GUE Fundamentals
Recreational pass to a Technical pass. These students must perform all skills, including 12-16, at a grade 4 or higher to qualify for registration to the Cave or Tech curriculum.
Equipment Requirements
Each student should have, and be familiar with, all of the following equipment:
1. 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.
2. Regulators: One of the second-stages must be on a 5- to 7-foot/1.5- 2-meter hose. One of the first
stages must supply a pressure gauge and provide inflation for a dry suit (where applicable).
3. Backplate System: A rigid and flat platform of metal construction with minimum padding, held to
a diver by one continuous piece of webbing. This webbing should be adjusted 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 hoped through the waistband prevents the system from riding up on the divers
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 on the left hip, the second should be placed in line with the
divers right collar bone, the third should be placed in line with the divers left collar bone, the
fourth and fifth should be affixed to the crotch strap to use while using a DPV or towing/stowing
gear. The harness below the diver’s arms should have small restrictive bands to allow for the
placement fo reserve lights. The system should retain a minimalist approach, with no unnecessary
components.
4. Buoyancy Compensation Device: A diver’s buoyancy compensation device should be backmounted
and minimalist in nature. It should be 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 50 lbs/25kg for a single tank and 80 lbs/40kg for double
tanks. Wing size and shape should be appropriate to the cylinder size(s) employed for training.
5. Wet Notes
6. One primary light: A primary light should be minimalist in design; it’s 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/10watt HID or
greater.
7. Two reserve lights: Reserve lights should be powered by two or three in-line non-rechargeable ccell
batteries, with a minimum of protrusions and a single attachment at its rear. The light should
be activated and de-activated by twisting the front bezel.
8. One spool with at least 100ft/30m of line per diver.
9. At least one surface marker buoy per diver.
10. At least on time-/depth-measuring device with stop watch and/or seconds display
11. Mask and fins: mask should be low-volume, fins should be rigid, non-split
12. At least one cutting device
13. Exposure suit appropriate for the duration of exposure