TDI – Advanced Trimix Course                  MORE TDI COURSES

The Advanced Trimix Course provides the training required to competently and safely utilize breathing gases containing helium for dives that require staged decompression, utilizing Nitrox and / or oxygen mixtures during decompression to a maximum depth of one hundred (100) metres. The objective of this course is to train divers in the benefits, hazards and proper procedures of utilizing custom oxygen / helium / nitrogen mixtures as breathing gases.

Qualifications of Graduates
Upon successful completion of this course, graduates may engage in technical diving activities utilizing custom Trimix mixtures without direct supervision as long as:
1. The diving activities approximate those of training.
2. The area of activities approximates those of training.
3. Environmental conditions approximate those of training.

Student Pre-Requisites
1. Be a minimum age of eighteen (18).
2. Have a minimum certification as an Extended Range Diver or Entry Level Trimix Diver (or equivalent).
3. Show proof a minimum of one hundred (100) logged dives with 25 deeper than one hundred (100) feet/ thirty (30) meters.
4. Prior logged experience w/ double cylinders and any other unfamiliar equipment. I.E. Dry suit

Course Structure and Duration
1. Four (4) dives with a minimum accumulated bottom time of one hundred (100) minutes
2. At least two (2) dives should be deeper than fifty five (55) msw / one hundred eighty (180) fsw.

Required Equipment
1. Bottom Mix Cylinder(s)
A. Cylinder volume appropriate for planned dive and student gas consumption.
B. Dual outlet valve, double manifold or independent doubles.
C. Labeled in accordance with TDI Standards.
2. Travel Mix Cylinder(s)
A. Cylinder volume appropriate for planned dive and student gas consumption.
B. Labeled in accordance with TDI Standards.
3. Decompression Mix Cylinder(s)
A. Cylinder volume appropriate for planned dive and student gas consumption.
B. Labeled in accordance with TDI Standards.
4. Suit Inflation Cylinder (required for dry suit divers only).
5. Regulators
A. Primary and primary redundant required on all bottom mix cylinder(s).
B. Submersible pressure gauges are required on all primary bottom mix cylinders.
C. A contingency use long hose second stage should be designated and appropriately rigged to facilitate air sharing at depth if necessary.
D. It is strongly recommended that all four (4) required regulators be DIN or all four (4) regulators be yoke.
6. Buoyancy Compensator(s) adequate for equipment configuration.
7. Redundant Depth and Timing Devices. Air decompression computers allowed for use as depth and timing devices.
8. Redundant Light System if required by site.
9. Ascent Reel with Lift Bag/Surface Marker Buoy
A. Adequate for maximum planned depth.
B. Minimum of twenty three (23) kg / fifty (50) lb. lift bag (a dump valve highly recommended).
10. Exposure suit adequate for the open water environment.
11. Line Cutting Device.
12. Underwater Slate (for decompression / contingency tables).

You will be expected to:
1. Be competent in skills required to graduate from any prerequisite TDI course (or equivalent)
2. Properly analyze all gas mixes to be used.
3. Calculate and mark MOD of each mix appropriately.
4. Demonstrate adequate pre-dive planning (limits based on team experience, gas consumption of individuals and of team as a whole, oxygen depth and time, inert gas depth and time, environment, contingency and so on).
5. Properly execute a planned (dives within all predetermined limits.
6. Satisfactorily complete TDI written exam.
7. Demonstrate mature and responsible judgement concerning dive planning and execution.
8. Maintain a high level of awareness and respect for environment in which all diving and dive preparation is conducted.
9. Log all dives.

Required Skill Performance And Graduation Requirements
Land or field skills
1. Demonstrate familiarity with basic and intermediate hand signals.
2. Select and prepare of equipment suitable for soft overhead environment with long decompression obligations.
3. Conduct team oriented drills for SMB deployment and gas switching procedure.
4. Drills for buddy rescue

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

Skills during dive
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 competence managing three stage cylinders including drop and recovery while maintaining position in the water column.
4. Ability to manage multiple failures in adverse conditions.
5. Complete a horizontal breath hold swim at depth for 20 meters with mask off or blacked out.
6. Deploy lift bag while sharing air on buddy's long hose.

In order to complete this course, students must:
1. Satisfactorily complete the TDI Trimix Course written examination.
2. Complete all open water requirements safely and efficiently.
3. Demonstrate mature, sound judgment concerning dive planning and execution.

*) START is Sdril (OOA drill and bubble check), Team checks, Air (gas matching), Route (entry/exit and planned path underwater, Tables (depth, duration, waypoints and schedule).