Open-Circuit Programs

Hypoxic Trimix

Intent

This program provides divers with the training necessary to:

Independently plan and conduct three-gas switch, multiple-stop decompression dives,

In a Twinset Total Diving System,

To a maximum depth of 330 feet,

Using trimix breathing gases,

Using decompression gas mixtures up to 100% oxygen,

With an equally- or more-qualified dive buddy.

Minimum Instructor Rating

An active status Hypoxic Trimix Instructor may conduct the Hypoxic Trimix program.

Student Prerequisites

Have logged at least:

100 total dives

30 dives deeper than 100 feet.

10 dives deeper than 150 feet.

20 dives requiring staged decompression with at least two (2) gas switches (not including training dives).

Have the following SSI certifications or an equivalent from a recognized training agency:

Technical Extended Range

Duration

Recommended hours for completion | 18.

Minimum Equipment

Students participating in this program must use at least the following equipment configuration:

A complete Twinset Total Diving System.

Including:

Three (3) stage cylinders.

In-Water Ratios

The student-to-instructor ratio is 3:1.

Depth Limitations

Maximum pool/confined water depth limit | 40 feet.

Maximum depth for Open Water Training Dives 1 and 2 | 130 feet.

Maximum depth for Open Water Training Dives 3 and 4 | 265 feet, with at least one dive deeper than 250 feet.

Maximum depth for Open Water Training Dives 5 and 6 | 330 feet.

At least one (1) dive must be to a depth of 295 feet.

Requirements For Completion

Complete all academic sessions and assessments as outlined in the instructor manual for Hypoxic Trimix.

Complete the program’s final exam.

Independently plan a full dive plan using the Extended Range Dive Planning sheets.

Complete the XR Water Fitness Evaluation as outlined in the SSI General Training Standards.

Complete at least one (1) pool/confined water skill development session, with a cumulative time of at least 90 minutes as outlined in the instructor manual for Hypoxic Trimix.

Complete at least six (6) open water training dives as outlined in the instructor manual for Hypoxic Trimix.

Training Conditions

Breathing Gas and Decompression

Open Water Training Dives 1 and 2 must be planned within the no-decompression limits of the student’s dive computer, dive planning software, or the SSI Combined Air/EAN Tables.

The total cumulative time for Open Water Training Dives 3-6 must be at least five (5) hours.

The primary plan decompression obligation (total time of all decompression stops including deep stops, if used) must not exceed 60 minutes for Open Water Training Dives 3 and 4.

The primary plan decompression obligation (total time of all decompression stops including deep stops, if used) must not exceed 90 minutes for Open Water Training Dives 5, 6, and any additional training dives.

Each open water training dive must include at least three (3) gas switches.

Environment

If environmental or water conditions make it unsafe or impractical to meet the cumulative time requirement, additional training dives should be scheduled.

Sequence

Open Water Training Dives 1 and 2 may only be conducted after the student successfully completes the equipment configuration session, the XR Water Fitness Evaluation, and all pool/confined water skill development sessions.

Open Water Training Dives 3 and 4 may only be conducted after the student successfully completes Open Water Training Dives 1 and 2.

Open Water Training Dives 5 and 6 may only be conducted after the student successfully completes all academic sessions and Open Water Training Dives 3 and 4.

Certification

Upon completion of all academic and in-water requirements, the SSI Professional may issue the program’s digital certification card.

The SSI Hypoxic Trimix certification entitles the holder to dive autonomously:

In environments similar to those of the diver’s training and experience,

To depths of either 265 or 330 feet, depending on the certification achieved,

Using trimix breathing gases,

With unlimited decompression stops,

With an equally- or more-qualified dive buddy.

Exception

The Hypoxic Trimix 265-feet certification is the same as the 330-feet certification, with one exception: if conditions do not permit, or the students cannot make the deepest dives, divers may become certified at 265 feet after the first four (4) open water training dives.

After developing experience, and with an equally- or more-qualified buddy, a diver qualified to 330 feet may dive to depths deeper than 330 feet.