TDI Advanced Nitrox Class 

Do you want to extend your bottom time while getting out of the water faster?

The TDI Advanced Nitrox class will help you do both. This course is typcially taught in conjunction with the TDI Decompression Procedures class and is one of the foundation courses for technical diving. During this class you will learn how to use a second Nitrox mixture during your ascent.  

This course examines the use of EAN-21 through 100 percent oxygen for optimal mixes to a depth of 130 feet. The objective of this course is to train divers in the benefits, hazards and proper procedures for utilizing EAN-21 through 100 percent oxygen for dives not requiring staged decompression.

Decompression Procedures or Intro To Tech may be combined with this course at the discretion of the instructor.

Note: Intro To Tech or remedial skills development may be required if the student is unable to demonstrate excellent bouyancy control and other basic skills. This is not the class to try out your new set of doubles for the first time.

Qualifications of Graduates

Upon successful completion of this course, graduates may engage in diving activities utilizing EAN-21 through 100 percent oxygen without direct supervision provided:

  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. Decompression Procedures
  2. TDI Extended Range Course

Student Prerequisites:

  1. Minimum age 15
  2. Minimum certification of TDI Nitrox Diver, or equivalent
  3. Show proof of 75 logged open water dives
  4. If this course is taught in conjunction with the TDI Decompression Procedures course, the minimum age is 18

Open Water Requirements

  1. Four dives are required with a minimum accumulated bottom time of 100 minutes
  2. If advanced nitrox is taught in conjunction with decompression procedures*, only a total of 6 dives are required, more may be conducted at the discretion of the instructor, with a maximum depth of 150 feet
  3. If Advanced Nitrox is taught in conjunction with Intro to Tech*, only a total of four (4) dives are required, more may be conducted at the discretion of the instructor, but all dives must be conducted at depths within the diver’s current level of certification and no dives should exceed 75 feet
  4. Only 2 dives from advanced wreck course may be credited towards the total dives required

Class Duration:

The Advanced Nitrox Course consists of required pre course homework, a minimum of one evening of classwork, and two full days of diving/training.

*A 3-way combination of TDI Intro to Tech, Advanced Nitrox and Decompression Procedures is permitted with a minimum of 8 dives required. The prerequisites for advanced nitrox and decompression procedures diver must be met for this combination before starting the program.

Academic Subject Areas:

  1. Physics a. Pressure review
  2. Physiology
    1. Hypoxia
    2. Oxygen toxicity
      1. Whole body oxygen toxicity units (OTU’s)
      2. Central nervous system (CNS)
    3. Nitrogen narcosis
    4. Nitrogen absorption and elimination
    5. Carbon dioxide toxicity
    6. Carbon monoxide toxicity
  3. Formula Work
    1. Best mix computations
    2. Maximum operating depth (MOD) of mixture computations
  4. Equipment Considerations
    1. Less than 40 percent oxygen content
    2. More than 40 percent oxygen content
  5. Dive Tables
    1. Equivalent air depth with any table
    2. Computer generated table
  6. Dive Computers
    1. Mix adjustable
    2. Oxygen (O2)integrated

  7. Dive Planning
    1. Operation planning
    2. Gas requirements
    3. Oxygen limitations
    4. Nitrogen limitations
  8. Common Mixing Procedures (instructor to demonstrate one method)
    1. Partial pressure blending
    2. Continuous blending
    3. Membrane separation system
  9. Decompression
    1. Enriched air nitrox (EAN) usage as a decompression gas i.e. 50/50, 80/20 etc
    2. Oxygen (O2) for decompression
  10. Advantages / disadvantages of multiple gas switches

The following open water skills must be completed by the student during all open water dives:

Land Drills

  1. Review of nitrox skills
  2. Demonstrate correct use of oxygen analyzer including optimal procedure for calibration
  3. Demonstrate adequate pre-dive planning
    1. Limits based on personal gas consumption.
    2. Limits based on oxygen exposures at planned depth with actual mix
    3. Limits based on nitrogen absorption at planned depth with actual mix
  4. Calculate and log CNS loading for each dive including cumulative exposure where appropriate
  5. Demonstrate understanding of gas labeling
  6. Demonstrate adherence to conventions regarding prep of equipment for oxygen (O2) service
  7. Program nitrox computer with appropriate oxygen percentage if used
  8. Properly execute the planned dive within all predetermined limits

Pre-dive Drills:

  1. Use START* before every dive
  2. Stress analysis and mitigation

*START is S-drill (OOA drill and Bubble Check), Team (buddy equipment checks), Air (gas matching), Route (entry/exit and planned path underwater), Tables (depth, duration, waypoints and schedule).

In-water Drills:

  1. Demonstrate buoyancy control; ability to hover at fixed position in water column without moving hands or feet
  2. Show good awareness of buddy and other team members through communications, proximity and team oriented dive practices
  3. Demonstrate ability to manage free flow from primary regulator in controlled fashion, shutdown cycle, and switch to back-up regulator
  4. Conduct appropriate safety stop while maintaining neutral buoyancy
  5. Demonstrate ability to share air with buddy as both recipient and donor in a controlled manner while maintaining position in water column
  6. Demonstrate correct body position; appropriate trim, such as horizontal / streamlined when moving forward
  7. Demonstrate proper stress analysis with self and dive buddy

In order to complete this course, students must:

  1. Satisfactorily complete the TDI Advanced Nitrox 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 equipment is required for each student:

  1. Alternative second stage octopus attached to a primary regulator or a redundant scuba unit; 13 cu ft minimum
  2. A submersible pressure gauge
  3. Depth gauge and automatic bottom timer and/or dive computer
  4. Buoyancy compensator device (BCD) with power inflator
  5. Line cutting device
  6. Exposure suit adequate for the open water environment
  7. Cylinder and regulator properly labeled and cleaned as required for EAN mixtures
  8. Access to oxygen analyzer

How Much Does It Cost?

The TDI Advanced Nitrox Course costs $325 for group classes and private courses are available. We schedule students together for group classes whenever possible unless a private class is specifically requested. Military and Public Service discounts are also available.

The course tuition covers your instruction, books, and certification card. Equipment rental (if needed), tank fills, quarry fees, and charter fees are additional.

Note: Participation in the Advanced Nitrox Class does not guarantee certification. Each student must complete the required number of dives, all the skills, and demonstrate that they are comfortable with planning and executing safe dives using Nitrox before they receive thier certification. If a student is unable to meet the course requirements additional training may be required.

What's Next?

Once you have completed the TDI Advanced Nitrox Course you may want to continue your exploration of technical diving by taking the Decompression Procedures Course.

Maximum depth for the course: 130 feet.