Purpose

The IANTD Tri-Mix course is designed as a culmination of pre-requisite courses to develop a truly competent technical diver and prepare qualified candidates for deep, mixed gas diving. Fine tuning skills and perfecting team communications, protocols and emergency procedures is key to success in this program.

Prerequisites

• Must meet the IANTD General Course Prerequisites for Technical Diver programs

• Must be qualified as a Normoxic Tri-Mix diver with a minimum of 200 logged dives of which at least 25 were to depths between 140' - 200'

• Must be a minimum of 18 years of age

• Be a non-smoker

• Entry into course by Instructor approval

Training Materials

IANTD Technical Encyclopedia and Tri-Mix Student Workbook

Duration

The IANTD Tri-Mix course includes fifteen hours of academics generally taught in five , three hour sessions as well as four dives completed over two days.

Course Content

The IANTD Tri-Mix course cumulatively includes a minimum of forty hours of instruction designed to provide an advanced understanding of mixed gas diving. Emphasis will be focused on extended exposures, equipment logistics, team support, contingency planning and the benefits of DPV use for deep exploration. Four dives will be completed to depths up to 330'.

Academic Topics

• IANTD organization

• Course Standards and Procedures

• Course completion requirements

• History of Mixed Gas diving

• Physiology

• Helium

• HPNS

• Counter Diffusion

• Inert gas absorption and elimination

• Bottom, travel and decompression gasses

• Logistics planning

• Project support and operational planning

• Emergency planning

• Omitted decompression

• Advanced decompression strategies

Surface Drills and Skills

• Multiple bottle gas switching protocols

• Advanced communications

• Spool, reel and guideline use review

In-water Skill Requirements

• Complete a valve shutdown drill in less than 1 minute

• Demonstrate efficient switch to stage cylinder while swimming

• Demonstrate efficient gas switching abilities and protocols while carrying multiple deco / stage cylinders

• Remove and replace stage cylinders while stationary and while swimming

• Remove and replace equipment including stages in less than two minutes

• Demonstrate efficient gas sharing while managing multiple stages

• Demonstrate efficient deployment of a backup light in under 30 seconds

• Demonstrate a mastery of navigation utilizing a compass and natural navigation techniques

Course Limits

• IANTD General Program Limits

• Maximum student to instructor ratio is not to exceed 3 to 1

• Maximum depth of 330'

• Two (2) decompression cylinders must be used in this course

• END (equivalent narcotic depth) may not exceed 100'

• No dives may be made with a PO2 greater than 1.6 for decompression and 1.4 for bottom gas

Equipment Requirements

• Twin, manifolded diving cylinders to carry sufficient gas supply for completion of dive following the rule of thirds

• A 7' hose with backup around neck attached with bungee necklace

• Pressure gauge (this should be a 2" gauge on approximately a 24" hose)

• Buoyancy control device ( should be a single "wing" style BCD)

• Mask and fins

• Means of monitoring depth and time. Depth gauge and bottom timer or a dive computer

• Dive tables must be used to backup computer or for control of the dive

• Appropriate exposure suit for 48 degree water temperature

• External dry suit inflation bottle and regulator

• Slate and pencil or Wet Notes

• Cutting tool. Small knife or medical shears

• Compass

• Surface alert device (whistle, Dive Alert etc...)

• Primary light (preferably a canister style light)

• Backup light

• Lift bag (preferably a 50lb. bag)

• Small reel or spool (75'-100' of line)

• 1 40 cu.ft. deco cylinder and 1 80 cu.ft. deco cylinder

• 2 decompression gas regulators with pressure gauges

• Surface marker buoy