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 any such TDI courses as Advanced Nitrox Course, Advanced Wreck Course, or Extended Range Course -- even as part of ongoing training towards Entry Level Trimix. The objective of this course is to train divers how to plan and conduct a standard staged decompression dive not exceeding a maximum depth of forty five (45) metres unless taught in conjunction with the Extended Range Course. The most common equipment requirements, gear set-up, and decompression techniques are presented. 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 may engage in decompression diving activities without direct supervision 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 Advanced Nitrox Course.
2. TDI Extended Range Course.
3. TDI Advanced Wreck Course.
4. TDI Entry Level Trimix.
Student Pre-Requisites
The student must:
1. Be a minimum age of eighteen (18).
2. Have a minimum certification of Open Water Diver.
3. Show proof of twenty five (25) logged open water dives.
Course Structure and Duration
Open Water Execution:
1. Four (4) dives are required.
2. If Advanced Nitrox is taught in conjunction with Decompression Procedures only a total of six (6) dives are required.
3. Only two (2) dives from Advanced Wreck course may be credited towards the total dives required.
Course Structure:
Required Minimum Equipment
The following equipment is required for each student:
[TDI Decompression Procedures Student Manual]
1. Primary Cylinder(s). Cylinder volume appropriate for planned dive and student gas consumption.
2. 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.
3. Depth gauge and automatic bottom timer and I or dive computer.
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 eleven (11) kg / twenty five (25) lb lift bag.
8. Oxygen Analyzer (may be supplied by the Instructor).
9. Exposure Suit adequate for the open water environment.
10. Underwater Slate.
Required Skill Performance And Graduation Requirements
The following open water skills must be completed by the student during open water dives:
1. Demonstrate adequate pre-dive planning
A. Limits based on personal and team gas consumption.
B. Exact dive and decompression profile.
2. Properly execute the planned dive within all pre-determined limits
A. Assembly of diver carried equipment.
B. Proper descent / ascent rates.
C. Proper staged stop procedures.
D. Monitoring of decompression status equipment (tables, computers, equipment).
3. Contingency Situations and Problem Solving (as appropriate by instructor)
A. Omitted decompression.
B. Extended bottom time profiles with increased decompression and re-calculated schedules.
C. Failure to deploy lift bag and reel.
D. Missed up-line or missed boat anchor.
E. Loss of decompression gas.
4. A safety stop of at least three (3) minutes shall be conducted on all No-Decompression dives and proper staged decompression stops whenever and wherever mandated.
5. Demonstrate the correct deployment of a lift bag using a dive reel and / or up-line.
6. Demonstrate (simulated) emergency gas sharing at a stationary depth not to exceed thirty (30) msw / one hundred (100) fsw.
7. 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.
8. Demonstrate the proper deployment, management and use of the bottom mix, decompression 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. Show appropriate and timely responses to instruction / signals from the instructor and 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.
2. Complete all open water requirements safely and efficiently.
3. Demonstrate mature, sound judgment concerning dive planning and execution.
TDI Medical Statement
TDI Technical Diver Registration Form
TDI Liability Release & Express Assumption of Risk
Home 
TDI Courses 
