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 45 msw unless taught in conjunction with the Extended Range or Advanced Wreck Course. The most common equipment requirements, gear set-ups, decompression techniques and decompression mixtures (including oxygen and nitrox) are presented. Upon successful completion of this course, graduates are qualified to enrol in the TDI Extended Range Course.

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 Course, Advanced Wreck Course, or Extended Range Course. 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 45 msw 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 utilise 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 enrol in:

1. TDI Advanced Nitrox Course.
   
2. TDI Extended Range Course.
   
3. TDI Entry Level Trimix.
   

Pre-requisites

• Minimum age 18 years
  
• Minimum cert of TDI Advanced Nitrox Diver (or equivalent)
  
• Minimum of 25 logged open water dives in the environment in which the course is being presented
  

Required Subject Areas

The TDI Decompression Procedures Manual is mandatory for use during this course but instructors may use any additional text or materials that they feel help present these topics. The following topics must be covered during this course:

1. Overview of decompression “safety stops” compared to required stops.
   
2. Physics
   
   • Pressure review.
     
3. Physiology
   
   • Mechanics of bubble formation.
     
   • Advantages of hyperoxic mixes for decompression.
     
   • Nitrogen Absorption and Elimination.
     
   • Carbon Dioxide Toxicity.
     
   • Ascent / Descent rates.
     
   • Hyperthermia.
     
   • Hypothermia.
     
   • Psychological aspects
     
     • Task loading.
       
     • Stress.
       
     • Panic.
       
     • Time Management.
       
     • Equipment.
       
4. Decompression Options
   
   • Air.
     
   • Nitrox.
     
   • Oxygen.
     
5. Equipment Considerations
   
   • Twin cylinder or single cylinder option, valve options.
     
   • Stage cylinder options.
     
   • Regulator Options.
     
   • Harness / BC options.
     
   • Computer, depth gauge, bottom timer options.
     
   • Ascent and navigation reels.
     
   • Lift bags/surface marker buoys for drifting or free decompression.
     
   • Jon-line or Garvin clips.
     
   • Proper weighting and buoyancy control during dive phase and decompression.
     
6. Dive Tables vs. Computers
   
   • Introduction and review of different models (Buhlmann, DCIEM, US Navy, etc).
     
   • Proper use of electronic multi-level dive computers for dive planning and decompression
     
     • Mix adjustable.
       
     • 02 integrated.
       
7. Dive Planning
   
   • Standard Operation
     
     • Gas requirements.
       
     • Oxygen limitations.
       
     • Nitrogen limitations.
       
   • Emergency planning
     
     • Omitted decompression.
       
     • Decompression sickness.
       
     • Equipment failure.
       
8. Procedures
   
   • Primary and Decompression Gas
     
     • Normal operations.
       
     • Failure, loss or inadequate emergency procedures.
       
     • Analysis and logging.
       
     • Safeguards on decompression supply regulators.
       
     • Rigging and deployment of decompression gear.
       
   • Descent
     
     • Methods of entry, down lines or free decent.
       
     • Organization of equipment carried on diver.
       
   • Ascent
     
     • Variable rates.
       
     • Trim and compensation.
       
   • Fixed or Drifting Decompression Methods
     
     • Up-lines fixed to bottom.
       
     • Reels and lift bags/surface marker buoys.
       
     • Free drifting stages or boat supplied.
       
     • Self-contained versus surface supply / rendezvous gas cylinders.
       
   • Support
     
     • From shore.
       
     • From descent line or fixed platform.
       
     • From live-aboard boat.
       

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
   
   • Limits based on personal and team gas consumption.
     
   • Exact dive and decompression profile.
     
2. Properly execute the planned dive within all pre-determined limits
   
   • Assembly of diver carried equipment.
     
   • Proper descent / ascent rates.
     
   • Proper staged stop procedures.
     
   • Monitoring of decompression status equipment (tables, computers, equipment).
     
3. Contingency Situations & Problem Solving (as appropriate by instructor)
   
   • Omitted decompression.
     
   • Extended bottom time profiles with increased decompression and re-calculated schedules.
     
   • Failure to deploy lift bag and reel.
     
   • Missed up-line or missed boat anchor.
     
   • Loss of decompression gas.
     
4. A safety stop of at least three 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 30 msw.
   
7. Demonstrate emergency deployment of a backup regulator or bail-out scuba system containing bottom mix at a depth not exceeding 30 msw.
   
8. Demonstrate the proper deployment, management and use of the bottom mix, decompression mix and travel mix (if used), including but not limited to:
   
   • Conservative gas management.
     
   • Depth control to avoid descending too deep for mix.
     
   • 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.

Required Equipment

The following are required for this course:

1. TDI Decompression Procedures Student Manual.
   
2. TDI Decompression Procedures PowerPoint.
   

Equipment you will need to buy prior to course;

• Depth gauge and automatic bottom timer or dive computer. – 2 devices required
  
• Regulator(s) – 2 bottom and 1 deco all in oxygen service and DIN.
  
• Submersible pressure gauges are required on bottom cylinder and each stage cylinder.
  
• Wing-style BCD bladder with at least 20 Kg lift for bolted twinset with harness and backplate
  
• Line cutting device
  
• Ascent Reel with Lift Bag /Surface Marker Buoy.
  
• Exposure Suit adequate for the open water environment.
  
• Underwater Slate.
  
• 2 meters black surgical tubing
  

You can hire all the above from us – see price list for costs. If Equipment is needed then a 10% discount will be applied over Price List. Please let us know in advance.

The Price includes gas but there is an additional fee for certification and manual - see price list . Also if more than one TDI course is booked for consecutive attendance and paid for in advance a 10% discount will apply to the total course costs (excluding certification fee).

Please also remember to bring your GP signed medical with you (form available on website).

Please also check out our terms and conditions, packages available, price list, and the medical statement from the booking pack or from our website, and feel free to ask any questions you may have.