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ANDP Diver

Adv. Nitrox & Deco Procedures
In a Nutshell

The TDI Advanced Nitrox and Decompression Procedures (aka ANDP)  combined course is the gateway to extended-range diving, teaching you how to safely manage accelerated decompression using high-oxygen gas mixes. 
 

Advanced Nitrox expands your knowledge of enriched air, refining buoyancy, gas management, and emergency procedures in the column of water, while Decompression Procedures introduces planned staged decompression diving to a max depth of 45m/150ft.


You'll master equipment setup, gas switching, and decompression strategies, gaining the skills to execute technical dives precisely and confidently. This is the foundation for deeper, more complex diving—whether you're heading toward advanced wrecks, deep reefs, or technical cave diving.
 

Minimum course duration: 5 days.

Who This Course Is For

This course is designed for certified divers who want to move into technical diving and planned decompression.
 

You should already be comfortable with:

  • Fundamental buoyancy and trim control

  • Basic gas management

  • Team awareness and communication

  • Emergency procedures

  • Stable equipment configuration
     

This course builds technical discipline and prepares divers for more complex diving environments.

Prerequisites

  • Minimum age: 18

  • TDI Nitrox (or equivalent)

  • Backmount: TDI Intro to Tech (or equivalent or proven experience)

  • Sidemount: TDI Sidemount (or equivalent or proven experience)

  • Minimum 50 logged dives

Skills & Challenges Ahead

As dives extend beyond no-decompression limits, new challenges emerge—task loading increases, gas management becomes more critical, and decompression obligations demand precise execution. Managing multiple gas mixtures and executing controlled ascents with staged decompression requires heightened situational awareness and disciplined buoyancy control.

Diving deeper and longer means greater exposure to physiological stressors such as oxygen toxicity, inert gas narcosis, and COâ‚‚ buildup. The ability to stay composed and execute emergency procedures—such as gas loss, omitted decompression, or equipment failures—is crucial.

The TDI Advanced Nitrox & Decompression Procedures course prepares you for these challenges, refining your skills in controlled ascent strategies, gas switching protocols, and contingency planning. With a focus on efficiency, precision, and problem-solving, you’ll develop the confidence to execute technical dives safely and effectively.

Training Content (overview)

In-water training includes:

  • Refinement of fundamental technical diving skills

  • Advanced buoyancy, trim, and propulsion with stage cylinders

  • Gas switching procedures and verification protocols

  • Positioning and control during decompression stops

  • Deployment and use of DSMB / lift bag for free-floating decompression

  • Management of multiple gas mixtures and depth-specific switches

  • Emergency gas-sharing and regulator failure management

  • Problem-solving in decompression scenarios (gas loss, valve failures, omitted stops)

Land-based training covers:

  • Gas analysis, labeling, and marking of decompression gases

  • Dive planning and contingency planning

  • Team gas matching and decompression schedule verification

  • Stage cylinder rigging and gas switch protocols

  • Land drills and procedural simulations

  • Thorough briefings and debriefings to reinforce every exercise

Academic presentations explore:

  • Decompression theory and ascent strategies

  • Physiological considerations (oxygen toxicity, COâ‚‚ retention, hypoxia)

  • Psychological factors and stress management

  • Decompression models, computers, and tables

Course Duration
 

Minimum durations shown

AN+DP

5 days

Divers who have not trained with CDT Mexico previously, or who have been inactive beyond defined timeframes, may require a 1-day skills assessment.

Get Ready

Training is not about collecting a card.
It’s about earning real autonomy, safety, and confidence.
The objective: divers who can plan and execute dives independently.

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