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TDI – Decompression Procedure Instructor Course
Introduction
This course examines the theory, methods and procedures of planned stage decompression diving. This program is designed as a stand-alone course or it may be taught in conjunction with such TDI courses as TDI Advanced Nitrox Instructor, TDI Advanced Wreck Instructor, or TDI Extended Range Instructor. The objective of this course is to train Instructors how to plan and conduct a standard decompression procedures course not to exceed a maximum depth of forty five (45) msw / one hundred fifty (150) fsw. The most common equipment requirements, gear set-ups, deco-techniques and decompression mixtures are covered. Students are permitted to utilize Enriched Air Nitrox mixes or oxygen for decompression provided the gas mix is within their current certification level.

Qualifications of Graduates
Upon successful completion of this course, graduates are entitled to teach a staged decompression course utilizing air, Nitrox and / or oxygen so long as:
1. The diving activities approximate those of training.
2. The areas of activities approximate those of training.
3. Environmental conditions approximate those of training.
Upon successful completion of this course, graduates are qualified to enroll in:
1. TDI Extended Range Instructor Course.
2. TDI Advanced Wreck Instructor Course.
3. TDI Entry Level Trimix Instructor Course.

Who May Teach
Who may teach this course:
1. Any active TDI Decompression Procedures Instructor Trainer.
2. Any TDI Extended Range Instructor Trainer.
3. Any TDI Trimix Instructor Trainer.

Student – Instructor Ratio
Academic:
1. Unlimited, so long as adequate facility, supplies and time are provided to insure comprehensive and complete training.
Confined Water (Swimming pool-like conditions):
1. N/A
Open Water (Ocean, lake, quarry, spring, river or estuary):
1. A maximum of four (4) students per Instructor. However, it is the instructor’s discretion to reduce this number as conditions dictate.

Student Pre-Requisites
The student must:
1. Be a minimum age of eighteen (18).
2. Have a minimum certification of TDI Advanced Nitrox Instructor or equivalent.
3. Have a minimum of one hundred fifty (150) logged dives.
4. Must have certified ten (10) students in SDI Deep Diver or Advanced Nitrox diver or equivalent.

Course Structure and Duration
Open Water Execution:
1. Four (4) decompression dives with a minimum accumulated bottom time of one hundred (100) minutes.
2. If Advanced Nitrox is taught in conjunction with Decompression Procedures only a total of six (6) dives are required.
Course Structure:
1. TDI allows instructors to structure courses according to the number of students participating and their skill level.
Duration:
1. The minimum number of classroom and briefing hours is six (6).

Administrative Requirements
The following is the administrative tasks:
1. Collect the course fees from all the students.
2. Ensure that the students have the required equipment.
3. Communicate the training schedule to the students.
4. Have the students complete the Liability Release and Medical history forms.
5. The Instructor should review the Liability Release and Medical Forms before starting on the course.
Upon successful completion of the course the Instructor must:
1. Complete the Student Registration Form and send the Registration Form to TDI HQ.
2. Award card and certificate.

Required Equipment
The following are required for this course:
1. Decompression Procedures Instructor guide
2. TDI Standard and Procedures Instructor Manual.

The following equipment is required for each candidate:
1. Primary Cylinder(s).
2. Cylinder volume appropriate for planned dive and student gas consumption.
3. Decompression Mix Cylinder(s).
A. Cylinder volume appropriate for the planned dive and student gas consumption with submersible pressure gauge.
B. Labeled in accordance with TDI Standards.
4. Regulator(s)
A. Primary and alternate 2nd stage required on all primary cylinders.
B. Submersible pressure gauges are required on all primary cylinders.
5. Buoyancy Compensator(s) adequate for equipment configuration.
6. Jon-line and other rigging lines as dictated by site conditions.
7. Ascent Reel with lift bag / surface marker buoy
A. Adequate for maximum planned depth.
B. Minimum of twenty three (23) kg / fifty (50) lb lift bag.
8. Depth gauge and automatic bottom timer and / or dive computer.
9. Exposure Suit adequate for the open water environment.
10. Oxygen Analyzer.
11. Underwater Slate.
12. Submersible dive tables – if desired.

6.9 Required Subject Areas
Instructor Trainers must use the Decompression Procedures Instructor Guide and the current TDI Standards and Procedures Instructor Manual but may also use any additional text or materials that they feel help present these topics.
1. Overview of decompression “safety stops” compared to required stops
2. Physics
A. Pressure review.
3. Physiology
A. Mechanisms of bubble formation.
B. Advantage of hyperoxic mixes for decompression.
C. Nitrogen Absorption and Elimination.
D. Carbon Dioxide Toxicity.
E. Ascent / descent rates.
F. Hyperthermia.
G. Hypothermia.
H. Psychological aspects: task loading, stress, panic, time management.
4. Decompression Options
A. Air.
B. Nitrox.
C. Oxygen.
5. Equipment Considerations
A. Twin cylinders or single cylinder options, valve options.
B. Stage cylinder options.
C. Harness / BC Option.
D. Computer, depth gauge, bottom timer options
E. Ascent and navigation reels.
F. Lift bags/surface marker buoys for drifting or free decompression.
G. Jon-line or Garvin clips.
H. Proper weighting and buoyancy control during dive phase and deco.
6. Dive Tables
A. Introduction and review of different models (DCIEM, U.S. Navy, etc).
7. Dive Computers
A. Mix adjustable.
B. 02 integrated.
8. Dive Planning
A. Standard Operation
I. Gas requirements.
II. Oxygen limitations.
III. Nitrogen limitations.
B. Emergency Planning
I. Omitted deco.
II. Decompression sickness.
III. Equipment failure.
9. Procedures
A. Primary and Decompression gas
I. Normal operations.
II. Failure, loss or inadequate emergency procedures.
III. Analysis and logging.
IV. Safeguards on deco supply regulators.
V. Rigging and deployment of deco gear.
B. Descent
I. Methods of entry, down lines or free decent.
II. Organization of equipment carried on diver.
C. Ascent
I. Variable rates.
II. Trim and compensation.
D. Fixed or Drifting Deco methods.
I. Up lines fixed to bottom.
II. Reels and lift bags/surface marker buoys
III. Free drifting stages or boat supply.
IV. Self-contained versus surface supply / rendezvous gas cylinders.
E. Support
I. From shore.
II. From descent line or fixed platform.
III. From live aboard boat.
10. Administration Procedures
A. Medical Form.
B. Waiver Forms.
C. Risk Management.
D. Registration forms.
E. Standards and Procedures.

Required Skill Performance and Graduation Requirements
The following skills must be completed by the Instructor candidate:
1. Prior to the dive, analyze the gas mixture in each cylinder, fill out the contents tag and facility Nitrox log.
2. Perform an advanced pre-dive plan and dive analysis (including risk assessment)
A. Predetermine the appropriate depth and time limits for the dive based upon personal ability, environmental conditions, and gas consumptions (personal and team).
B. Predetermine the limits associated with nitrogen, including NDLs and EAD.
C. Assembly of diver carried equipment.
3. Properly execute the planned dive within all pre-determined limits
A. Proper descent and ascent rates.
B. Proper staged deco stop procedures.
C. Monitoring the status of staged deco equipment, (tables, computers, bottles, regulators, etc).
4. Contingency Situations and Problems Solving (as appropriate by instructor)
A. Omitted decompression.
B. Extended bottom time profile with increased deco and recalculation.
C. Failure to deploy lift bag / surface marker buoy and reel.
D. Missed up-line or missed boat anchor.
E. Loss of deco gas.
5. A proper stop of at least three (3) minutes shall be conducted on all dives and proper staged decompression stops whenever and wherever required.
6. Demonstrate the correct deployment of a lift a bag / surface marker buoy using a dive reel and / or up-line.
7. Demonstrate (simulated) emergency gas sharing at a stationary depth not to exceed thirty (30) msw / one hundred (100) fsw.
8. Demonstrate emergency deployment of a backup regulator or bail-out scuba system containing bottom mix at a depth not exceeding thirty (30) msw / one hundred (100) fsw.
9. Demonstrate the proper deployment, management and use of the bottom mix, deco-mix and travel mix (if used), including but not limited to:
A. Conservative gas management.
B. Depth control to avoid descending too deep for mix.
C. Demonstrate buoyancy control and awareness throughout the dive.
In order to complete this course, students must:
1. Satisfactorily complete the TDI Decompression Procedures Course written examination and be able to adequately explain each answer to a prospective student.
2. Demonstrate mature, sound judgment concerning training, dive planning and execution
3. Complete all open water requirements safely and efficiently.
4. Demonstrate proficiency in teaching Staged Decompression.
5. One graded presentation on Decompression Procedures topic.
Updated 9 May 2003