Extended range 55m

PSA - Extended Range

This course provides the skills for Deep Air Diving with the use of more than one Rich Nitrox Mix (up to 100%) as decompression gas. The course covers further equipment configuration for deep diving (more stages differing sizes), trapeze use, and the use of advanced decompression equipment (obligatory emergency extra deco gas for team). Plus new training skills when working with different 'Team' sizes to challenge your personal stress limits, Narcosis Management, improve and build experience required to competently utilize air for dives up to 55msw that require staged decompression, utilizing nitrox mixtures and oxygen during decompression.

An invaluable stepping stone course which introduces alot of skills commonly used on trimix dives particually for the UK diver. ERD progresses your skills to work towards the ultimate goal of Trimix. You will be gaining the required technical experience for this level and then be more ready for the next Trimix level step. The ERD course is also a min requirement for such areas as Bikini that offer 55m dives and do not have helium for Trimix divers.

Course Cost

  • £508
  • £467 - Club Rate
  • Add £150 to package if you also want Tec 50 for dual passport

Course Format

  • Five-day course
  • One-day classroom
  • Confined Dives - discretion of instructor if required to refresh skills
  • Three days for the four open water dives

Course Equipment Requirements

A. Twin cylinders with sufficient volume to complete course requirements (minimum combined volume of 4000 liters (140 cubic feet).

     DIN valves are HIGHLY recommended, and both valves must be the same.
B. 2 Oxygen clean stage cylinders with sufficient volume for dive plan.
C. Four regulators, one with a long hose (minimum length 1.5 meters (5 feet)) connected to primary second stage.
D. Pressure gauge x 2 (one for back gas and one for decompression gas). 3 must be used if diving an independent twin

     cylinder configuration.
E. LP hoses for BCD inflation and dry suit if used.
F. BCD with sufficient lift (a minimum of 27 Kg or 60lb) to adequately support the required dive equipment and raise a fellow diver in

    an emergency.
G. A redundant inflation device in the form of a double bladder BCD.
H. Back plate and harness (recommended to have at least one quick release shoulder clip). Other types of BCDs are permitted;

     however, many ERDIS prefer the back plate and wings.
I. Thermal protection suitable for dive environment.
J. Dive lights if required with a least one redundant.
K. Dive computer plus redundant timing and depth device(s). Computer must be suitable for course. If a computer is not used then

     backup slates and tables must be carried. PSAI recommends the use of back up tables even when using computers.
L. Mask plus redundant mask.
M. Surface Marker Buoy (SMB/lift bag) (orange) SMB/lift bag (yellow) plus redundant bag and reel.

N. Reel(s).
O. Cutting Device.
P. Fins.
Q. 2 Slates and pencils or wet notes.

Curriculum Requirements
The PSAI Extended Range Nitrox Diver course requires the use of the PSAI Extended Range Nitrox Diver manual. This manual will have all the necessary information to appropriately cover, in the detail necessary for this level of certification, the following areas of information:

A. History of Extended Range Nitrox Diving.

    1. Early techniques of Deep Air Diving.
    2. Evolution of Extended Range Nitrox Diving Courses.             
    3. PSAI’s involvement in Extended Range Nitrox Diving Courses.

B. Physical Principles of Enriched Air Diving.

    1. Pressure.
    2. Boyle’s Law.
    3. Dalton’s Law.
    4. Charles’ Law.

C. Physiological Principles of Extended Range Nitrox Diving.

    1. Gases Appropriate for Extended Range Nitrox Diving.
    2. Hazards of Excess           
    3. Oxygen.
    4. Decompression Models.
    5. Accelerated Decompression.

D. Equipment for Extended Range Nitrox Diving.

    1. Standard Equipment.
    2. Cylinder and Valve Considerations.
    3. Manufacturer’s Recommendations.
    4. Stage/Decompression Cylinder Recommendations.
    5. Regulator Selection. 
    6. Buoyancy Control Device (BCD) Considerations.
    7. Redundancy Requirements.
    8. Organization and Rigging of Extended Range Nitrox Equipment
    9. Trapeze discussion.

E. Dive Planning. Equivalent Air Depth and Tables for Nitrox.

    1. Use of Dive Computers.
    2. Extended Range Dive Planning Tables.
    3. Computer Generated Dive Profiles.
    4. Support Procedures.
    5. Nitrogen and Oxygen Limitation Review.
    6. Gas Management Planning.

a. Bottom Gas Requirements.
b. Decompression Gas Requirements. Descent and Ascent Techniques and Considerations.
a. Down Lines.
b. Navigation from Shore or Vessel, and return.

Course Completion Performance Requirements
To be awarded the Professional Scuba Association International’s Extended Range Nitrox Diver certification, the student(s) must:

A. Attend all academic sessions.
B. Successfully master all academic and in-water skills.
C. Correctly demonstrate proper calibration of an oxygen analyzer and then properly analyze the oxygen content of all cylinders (including air cylinders) used for required dives.
D. Complete the PSAI Extended Ranger Nitrox Diver written examination with a score of at least 80%. All questions shall be correctly answered or remediated and explained.
E. Conduct the open water dives with appropriate skill and attention to all dive parameters and requirements, including maximum

    operating depths and adherence to decompression stop depths and times.
F. Perform a minimum of two (2) SMB deployments for the purpose of decompression depth reference. The student(s) will demonstrate

    the skill necessary to deploy the SMB in an expeditious manner, completing the deployment in less than one (1) minute.
G. Demonstrate the procedure to identify and isolate a malfunctioning bottom mix regulator. This skill shall not be conducted deeper than  40 meters (130 feet).
H. Demonstrate navigational techniques appropriate for the Extended Range dives performed.

I. One training dive shall include decompression with stops beginning at 12 meters (40 feet), with a total decompression of a minimum

   of 30 minutes. This may be actual or simulated decompression.
J. Log the required dives.

The PSAI instructor is responsible for ensuring that the Extended Range Nitrox Diver student(s) has demonstrated the appropriate respect and understanding for diving with Extended Range Nitrox diving gases. If the student(s) fails to maintain proper depth control, gas management awareness, buddy awareness, etc., the instructor must require additional training until the appropriate standards are achieved prior to certification.

Open Water Dives

  • Min 6 ERD dives are required with a student to instructor ratio of 3:1.
  • 6 dives greater than 30m but less than 55m.
    • Dives 1-2 in 30m+
    • Dives 3-4 in 40m+
    • Dive 5 in 50m+
    • Dive 6 max depth 55m
    • Two of the dives must be in the 50 to 55m range.


Advanced Nitrox Diver or equivalent. Min 75 dives logged with 20 decompression dives deeper than 30m.