A diver (Tony Youseman) on one of the quadruple propellersRebreather training in Malta.Santi drysuit and heating system on sale here,Rebreather diver in the red seaTDI Mixed Gas Course

IANTD Advanced Recreational Trimix

IANTD Advanced Recreational Trimix


This Program is designed to extend the diver’s knowledge in the use of EANx for Sport diving. It further develops diving skills and provides a greater understanding of the EANx concept of diving. It is also intended to supplement the skills of Recreational Trimix Divers.

The Program employs EANx mixes from 21% oxygen to a maximum of 1.5 PO2 combined with a Helium content that maintains an END no greater than 80 fsw (24 msw) may be used.

This program qualifies divers to dive to 160 fsw (48 msw) and perform decompression stops required dives up to 15 minutes.


What do I need to start?


IANTD Advanced Recreational Trimix Diver Student Kit.

A safety or decompression gas cylinder (if used) rigged as either a pony or stage cylinder. Gas cylinders must be oxygen clean and oxygen serviceable where needed.


What will I do?


All lectures completed with IANTD Course-specific Slides pertaining to the theory in the IANTD

Advanced Recreational Trimix Diver Student Kit.

This Program must include a minimum of 120 minutes of OW bottom time completed within 4 dives, 2 of which must be to depths between 100 fsw (30 msw) and 160 fsw (48 msw). If combined with a Deep Diver Program, the total dive time for both Programs must include a minimum of 160 minutes completed within 6 or more dives. Even if the time and skill requirements are met within fewer than 6 dives, the minimum 6 dives must be made. If combined with a Deep Diver Program 3 dives must be made to depths between 100 fsw (30 msw) and 160 fsw (48 msw). All dives deeper than 80 fsw (24 msw) must be made on Recreational Trimix mixtures.

Students are taught the use of Recreational Trimix mixtures from 28% to a maximum of 40% oxygen and with the helium content having an END no greater than 80 fsw (24 msw) for diving. EANx mixtures of 1.5 PO2 oxygen should be used for safety and decompression stops.


Program Limits


There may be no more than 4 students per Instructor. This ratio may be increased by 2 students for each assisting IANTD Divemaster, up to a maximum of 8 students with 2 IANTD Divemasters per class session.

No dives may be conducted to depths greater than 160 fsw (48 msw). Adequate He must be used to provide an END no Greater than 80 fsw (24 msw)

All dives must be conducted using EANx or Trimix (maximum 40% oxygen) as a bottom mix. PO2’s as high as 1.5 may be used at the decompression or safety stops.

All appropriate safety or required decompression stops must be performed.

Mandatory decompression stops are limited to a maximum of 15 minutes


Water Skills Development


A confined water session must be completed before conducting any OW dives.

Demonstrate proficiency in a variety of dive techniques and employ precision buoyancy control. Swim in a simulated out-of-air situation (without breathing, and exhaling slowly) without a mask for a distance of at least 50 feet (15 meters), and commence gas sharing; or appropriate Rebreather gas management drill for out-of air diver. While gas sharing, swim for 3 minutes, then replace and clear mask.

On an OW dive, demonstrate dive planning abilities, especially for avoiding CNS exposure risk.

On at least two dives use Recreational Trimix with a minimum of 28 % oxygen and a maximum of 40% oxygen and adequate Helium to provide an END no greater than 80 fsw (24 msw)

On all dives using Helium do a safety stop at 30, 20 and 15 fsw (9, 6 and 4.5 msw) for a minimum of 1 minute each or a safety stop at 30 fsw followed by a if needed and planed decompression stops at 20 and 15 fsw (6 and 4.5 msw) for no more than 10 minutes maximum based on EAN 50 as a decompression gas

Perform a gas sharing ascent using the alternate second stage.

Perform gas switches to a decompression gas mixture no greater than 1.5 PO2 on at least two dives

Perform valve shutdowns on each dive.

Deploy lift bag 2 times, using it as an ascent platform.

Demonstrate a safe attitude and awareness to the Instructor’s satisfaction.

Remove and replace tank and BCD at a depth greater than 20 fsw (6 msw).

Remove and replace tank and BCD at surface.

Demonstrate acceptable navigation / orientation abilities.

In an area where a depth is attainable beyond the planned depth, evaluate that the student has the discipline not to exceed the dive plan.

Demonstrate accident management / control techniques as described in text.

If entering the Program based on previous experience, complete the IANTD Deep Diver water skills.

Recommended watermanship evaluation, to be completed during the Advanced EANx course (80%= passing (80 / 100 points)


Skill One

Swim for a distance of 900 feet (270 meters) underwater in SCUBA gear. Score 25 points if completed in less than 7 minutes, and subtract one point for each additional 30 seconds required to complete the skill.


Skill Two

Swim for a distance of 50 feet (15 meters) in SCUBA gear without breathing, then commence gas sharing and swim for a distance of 250 feet (75 meters) without a mask.


Skill Three

Remove SCUBA gear underwater and perform a free ascent to the surface. Take three breaths, perform a surface dive, and don SCUBA gear. Repeat removal and replacement on surface. Score each as follows, then average the two scores for the overall skill score.


Skill Four

Simulated emergency lift bag ascent from a depth no shallower than 50 feet (15 meters), including a 3-minute safety stop. Evaluate on skill in deploying lift bag and on maintaining a tight reel and neutral buoyancy during safety stop. Score 25 points if performed correctly, and subtract 3 points for each mistake made, or five points if the student jams the reel or has to repeat the skill.


How long will it take?


The IANTD Advanced Recreational Trimix Course will be conducted over three days. The first day consists of an intensive theory session followed by a pool skills development course. Day 2 and 3 are conducted in open water and are based around skills practice and assessment


What will I need?


Must be qualified as an IANTD Recreational Trimix Diver or Nitrox Diver and IANTD Deep Diver with proof of a minimum of 30 logged dives or sufficient experience to satisfy the instructor that the student has the ability and knowledge to continue into this level of training.

Must be a minimum of 15 years of age with a parent or guardian authorization, or a minimum of 18 years of age without guardian approval.


What can I do after this?


The next step is the IANTD Normixic Trimix Course. Taking you to 65m on a safe mix and learning further gas planning and management skills, this is the next step in your technical diving career

International Association of Rebreather Trainers International Association Nitrox and Technical Diver Padi Tec Rec Technical Diving International