I. 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 Advanced Nitrox Instructor, Advanced Wreck Instructor, or Extended Range Instructor.

II. COURSE OBJECTIVES
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 150 fsw I 45 msw. 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.

III. QUALIFICATIONS OF GRADUATES
A. 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 area of activities approximate those of training
3. Environmental conditions approximate those of training
B. 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

IV. WHO MAY TEACH THIS COURSE
This course may be taught by any active TDI Decompression Procedures
Instructor Trainer, Extended Range Instructor Trainer, or Trimix Instructor
Trainer.

V. INSTRUCTOR to INSTRUCTOR TRAINER RATIO
A. Classroom
Unlimited, so long as adequate facility, supplies and time are provided for comprehensive coverage of course materials and the TDI written exam.
B. Open water
Maximum of 4 Candidates per TDI Instructor Trainer is allowed. This ratio should be reduced accordingly for less than ideal environmental conditions or operational constraints.

VI. INSTRUCTOR CANDIDATES PRE-REQUISITES
A. Minimum age 18
B. Minimum certification of TDI Decompression Procedures diver and TDI Advanced Nitrox Instructor or equivalent
C. Proof of 10 certified advanced nitrox level divers or SDI Deep Diver
D. Minimum of 150 logged dives

VII. REQUIRED COURSE MINIMUMS
A. Classroom Hours 6
B. Open water Dives 4 decompression dives with a minimum accumulated bottom time of 100 minutes

VIII. REQUIRED EQUIPMENT
The following equipment is required for each candidate
A. Primary Cylinder(s)
Cylinder volume appropriate for planned dive and student gas consumption
B. Decompression Mix Cylinder(s)
1. Cylinder volume appropriate for the planned dive and student gas consumption with submersible pressure gauge
2. Labeled in accordance with TDI Standards
C. Depth gauge and automatic bottom timer and I or dive computer
D. Regulator(s)
1. Primary and alternate 2nd stage required on all primary cylinders
2. Submersible pressure gauges are required on all primary cylinders
E. Buoyancy Compensator(s) adequate for equipment configuration
F. Jon-line and other rigging lines as dictated by site conditions
G. Ascent Reel with lift bag / surface marker buoy
1. Adequate for maximum planned depth
2. Minimum of 50 lb lift bag
H. Exposure Suit adequate for the open water environment
I. Underwater Slate

IX. REQUIRED SUBJECT AREAS
The following topics must be covered during this course. Instructor Trainers must use the Decompression Procedures Instructor Guide and the current TDI Standards & Procedures Instructor Manual but may also use any additional text or materials that they feel help present these topics.
A. Overview of decompression “safety stops” compared to required stops
B. Physics
1. Pressure review
2. Formulas for solving dive planning problems
C. Physiology
1. Mechanisms of bubble formation
2. Advantages of hyperoxic mixes for decompression
3. Nitrogen Absorption and Elimination
4. Carbon Dioxide Toxicity
5. Ascent / descent rates
6. Hyperthermia
7. Hypothermia
8. Psychological aspects: task loading, stress, panic, time management
D. Decompression Options
1. Air
2. Nitrox
3. Oxygen
E. Equipment Considerations
1. Twin cylinders or single cylinder options, valve options
2. Stage cylinder options
3. Harness / BC Option
4. Computer, depth gauge, bottom timer options
5. Ascent and navigation reels
6. Lift bags/surface marker buoys for drifting or free decompression
7. Jon-line or Garvin clips
8. Proper weighting and buoyancy control during dive phase and deco
F. Dive Tables
Introduction and review of different models (DCIEM, U.S. Navy, etc) G. Computers 1. Mix adjustable
2. 02 integrated H. Dive Planning
1. Standard Operation
a) Gas requirements
b) Oxygen limitations
c) Nitrogen limitations
2. Emergency Planning
a) Omitted deco
b) Decompression sickness
c) Equipment failure procedures
I. Procedures
1. Primary and Decompression gas
a) Normal operations
b) Failure, loss or inadequate emergency procedures.
c) Analysis and logging
d) Safeguards on deco supply regulators
e) Rigging and deployment of deco gear
2. Descent
a) Methods of entry, down lines or free decent
b) Organization of equipment carried on diver

3. Ascent
a) Variable rates
b) Trim and compensation
4. Fixed or Drifting Deco methods
a) Up lines fixed to bottom
b) Reels and lift bags/surface marker buoys
c) Free drifting stages or boat supply
d) Self-contained versus surface supply / rendezvous gas cylinders
5. Support
a) From shore
b) From descent line or fixed platform
c) From live aboard boat
J. Administration Procedures
Medical Form, Waiver Forms, Risk Management, Registration forms, Standards and Procedures

X. REQUIRED OPEN WATER SKILLS
The Instructor candidate must complete the following skills
A. Prior to the dive, analyze the gas mixture in each cylinder, fill out the contents tag and facility nitrox log
B. Perform an advanced pre-dive plan and dive analysis (including risk assessment)
1. Predetermine the appropriate depth and time limits for the dive based upon personal ability, environmental conditions, and gas consumptions (personal and team)
2. Predetermine the limits associated with nitrogen, including NDLs and EAD
3. Assembly of diver carried equipment.
C. Properly execute the planned dive within all pre-determined limits
1. Proper descent and ascent rates
2. Proper staged deco stop procedures
3. Monitoring the status of staged deco equipment, (tables, computers, bottles, regs, etc)
D. Contingency Situations & Problems Solving (as appropriate by instructor)
1. Omitted decompression
2. Extended bottom time profile with increased deco and recalculation
3. Failure to deploy lift bag / surface marker buoy and reel
4. Missed up-line or missed boat anchor
5. Loss of deco gas
E. A proper stop of at least three minutes shall be conducted on all dives and proper staged decompression stops whenever and wherever required
F. Demonstrate the correct deployment of a lift a bag / surface marker buoy using a dive reel and / or up-line
G. Demonstrate (simulated) emergency gas sharing at a stationary depth not to exceed 100 fsw / 30 msw
H. Demonstrate emergency deployment of a backup regulator or bail-out scuba system containing bottom mix at a depth not exceeding 100 fsw /30 msw
I. Demonstrate the proper deployment, management and use of the bottom
mix, deco-mix and travel mix (if used), including but not limited to
1. Conservative gas management
2. Depth control to avoid descending too deep for mix
3. Demonstrate buoyancy control and awareness throughout the dive

XI. GRADUATION REQUIREMENTS
In order to complete this course, Instructors candidates must:
A. Satisfactorily complete the TDI Decompression Procedures Course written examination and be able to adequately explain each answer to a prospective student.
B. Demonstrate mature, sound judgment concerning training, dive planning and execution
C. Complete all open water requirements safely and efficiently
D. Demonstrate proficiency in teaching Staged Decompression
E. One graded presentation on Decompression Procedures topic.

XII. SUPPORT MATERIALS
A. Instructor Registration
B. Decompression Procedures Instructor guide
C. TDI Standard & Procedures Instructor Manual