Underwater scene showing a diver wearing a helmet and suit, holding a large white tube or pipe, with dark water and a rocky underwater surface nearby.

Advanced Nitrox & Deco Procedures (AN/DP)

The TDI Advanced Nitrox and TDI Deco Procedures courses are the first step in the technical diving progression. Typically taught together concurrently, AN/DP certifies divers to a maximum depth of 50 metres/150 feet, with the use of up to 100% oxygen during staged decompression dives.

This combined course picks up where Intro to Tech (ITT) leaves off and offers a more in-depth look at technical decompression diving, including:

  • Decompression theory, including a historical overview, with a focus on modern Haldanian models, and risk factors for decompression stress (e.g., cold, dehydration, etc)

  • Physics and physiology relating to diving with gas mixes containing more than 40% oxygen and accelerated decompression

  • Equipment considerations, cylinder labeling, analyzing gas mixtures, gas blending procedures, and oxygen service ratings for using gases with more than 40% oxygen

  • Decompression dive planning including gas choices, gradient factors, and emergency and contingency procedures (equipment failures, catastrophic gas loss, omitted decompression, navigational errors, etc.)

  • Decompression diving procedures including decompression schedules, gas switching, team communication, and SMB/lift bag deployment

This course examines the theory, methods, and procedures of planned stage decompression diving using 50% and 100% oxygen. We will spend the first few days learning skills in the springs, and then go off-shore for a final day of ocean diving so that you get experience with deco procedures in both environments. Costs of the boat charter are not included in prices below. At least two of the six dives will be deeper than 100’.

This class is taught in sidemount or backmount doubles. For safety reasons, you must be proficient with trim and buoyancy in your chosen configuration prior to taking this course. If you are new to technical configurations, this course can be combined with Intro to Tech, which will introduce you to backmount doubles and the foundations of technical diving (tech-level trim, buoyancy, finning, etc).

We are happy to help arrange rental gear, including AL40s for deco oxygen and regulators - please let us know what rentals you will need. Please talk to us prior to purchasing any gear for this course. A limited selection of complimentary rental gear may be available through Spring Run Diving upon request.

Prerequisites: AOW, Nitrox, and minimum 25 logged dives (Intro to Tech and 100+ dives recommended). Proficiency in backmount doubles or sidemount required.

Gear Configuration: Sidemount or Backmount Doubles

Course Details: TDI Advanced Nitrox and TDI Deco Procedures

Total time commitment: 3-4 days (6 dives); max depth 150’.

Minimum age: 18+ years or older

Maximum Course Size: 2 Students

Course Cost: $900 USD* - Does not include cost of boat charters. Does not include cost of gear rentals (if required). Additional fees may be required for air fills, transportation, and dive site entrance cost. Contact us for more information.