A technical diver handling decompression stage cylinders during a dive

Photo by Teemu Virtanen · CC BY-SA 3.0

OC Tech (100m)TDI

Advanced Trimix

Official course standards ↗Last updated September 7, 2026

Advanced technical diving course extending trimix diving into hypoxic gas territory at depths exceeding 70m/230ft. Teaches hypoxic gas planning, extended decompression management with multiple gases, and equipment redundancy required at extreme depths. Represents the top of open-circuit depth progression before rebreather training.

Centres that teach this course

17 dive centres in the directory publish a price for this exact certification, checked Sep 2026. Each centre's own wording is shown beneath its name. Ranges cover whole-course prices only — where a centre charges per day or per dive, its rate is listed separately below, since a daily figure is not comparable with a course total.

€900 – €5,000across 8 centres pricing in Eurofrom ≈ $1,009
$1,900 – $2,400across 2 centres pricing in US Dollar
  • Cenote Cave DivingMexico
    Advanced Trimix Diver TDI
    1 student$1,900
    2+ students (10% off)$1,710
    $1,900
    total
  • Horizon DiversUnited States
    Advanced Trimix (TDI or IANTD)one price, several agencies
    $2,400
    total

Charged by the day or dive rather than as a course price:

  • Under The JungleMexico
    Advanced Trimix
    private$345/day→ $1,725 for the 5-day minimum
    per diver in a group$295/day→ $1,475 for the 5-day minimum each
    $345
    per day
  • Cave AdventurersUnited States
    Advanced Trimix
    Private class$550/day→ $2,200 for the 4-day minimum
    Group class$450/day→ $1,800 for the 4-day minimum each
    $550
    per day
THB 60,000 – THB 80,000across 3 centres pricing in Thai Bahtfrom ≈ $1,790
One centre publishes a price in Indonesian Rupiah.
One centre publishes a price in Philippine Peso.
  • Tech AsiaPhilippines
    TDI Advanced Trimix
    ₱60,000
    total

Same training under a different agency

16 centres

A separate set of centres, teaching Hypoxic / Advanced Trimix under a different agency. These are not the same certification — the standards and the card differ — but they cover the same depth and scope, which is why centres price them alike. Every row here names whose rating it is, and none of them is counted above.

€800 – €5,000across 12 centres pricing in Eurofrom ≈ $897
$756 – $2,000across 3 centres pricing in US Dollar

Charged by the day or dive rather than as a course price:

  • Protec MexicoMexico
    Trimix Level 2PSAI
    1 student$470/day→ $2,820 for the 6-day minimum
    2+ students$420/day→ $2,520 for the 6-day minimum each
    $470
    per day
  • Third Dimension DivingMexico
    Hypoxic Trimix DiverIANTD
    $295/day→ $1,475 for the 5-day minimum
    $295
    per day
THB 50,000 – THB 63,000across 4 centres pricing in Thai Bahtfrom ≈ $1,491
IDR 20,700,000across 2 centres pricing in Indonesian Rupiahfrom ≈ $1,153
One centre publishes a price in Philippine Peso.
  • Tech AsiaPhilippines
    PADI Tec TrimixPADI TecRec
    ₱34,000
    total

These prices are not like-for-like. Two centres can charge very differently for the same certification because they include different things. One price may cover twinsets, stages, deco gas and cylinder rental for every training dive, a dedicated classroom for the theory, boat or transport to the site, and the agency's registration and materials; another may be tuition only, with all of that charged separately — or the other way round, with a centre bundling in extras the first leaves out. Class size, whether the course is one-to-one, and how many days are allowed for it move the figure too. Check what each centre's price includes before comparing them, and confirm with the centre before booking.

Consumables are usually extra. Sorb, helium, O₂ and other fills, park and cenote fees, certification fees and rental are commonly charged on top.

Packages combining several certifications, upgrades from an existing one, and open-ended day rates are excluded — none of them is the standalone price of this course, and including them would move the figures away from what a new student can actually book.

Prerequisites

TDI Extended Range Diver or TDI Trimix Diver; Minimum 100 logged dives; Minimum age 18

Standards

What a diver must demonstrate to pass this course — not always published by the certifying agency.

Minimum 4 dives with 100 minutes accumulated bottom time. At least 2 dives deeper than 70m/230ft. In-water skills: gas management at extreme depth, multi-stage decompression execution, buoyancy control at pressure, emergency procedures with stage cylinders. Competency in hypoxic gas calculations and extended decompression gas switching.

Instructors Teaching This Course

Dive Centres Offering This Course

We're still building out the directory country by country, so this list isn't every instructor or dive centre teaching it in the world — more locations are coming soon.

Common questions about TDI Advanced Trimix

How much does TDI Advanced Trimix cost?

Published prices for TDI Advanced Trimix range across 15 centres in the TecDiveTools directory — roughly US$900 to US$5,650 at current exchange rates. In each centre's own currency: €900–€5,000 (8 centres), THB 60,000–80,000 (3 centres), $1,900–$2,400 (2 centres), IDR 17,000,000 (1 centre) and ₱60,000 (1 centre). 2 centres charge by the day instead, which is not comparable with a course total. Prices differ mainly in what they include, so compare the inclusions before comparing the numbers. Prices were last checked in September 2026.

How long does TDI Advanced Trimix take?

Between 4 and 8 days, based on the durations 9 centres publish for it. The time depends on the centre's schedule, weather, and how quickly the required skills are demonstrated — agencies set a minimum number of dives, not a fixed number of days.

What are the prerequisites for TDI Advanced Trimix?

TDI's standards require: TDI Extended Range Diver or TDI Trimix Diver; Minimum 100 logged dives; Minimum age 18.

What is the minimum age for TDI Advanced Trimix?

TDI's standards state: Minimum age 18.

How many dives do I need before starting TDI Advanced Trimix?

TDI's standards state: Minimum 100 logged dives.

What does TDI Advanced Trimix training involve?

According to TDI's published standards: Minimum 4 dives with 100 minutes accumulated bottom time. At least 2 dives deeper than 70m/230ft. In-water skills: gas management at extreme depth, multi-stage decompression execution, buoyancy control at pressure, emergency procedures with stage cylinders. Competency in hypoxic gas calculations and extended decompression gas switching.

What is the equivalent of TDI Advanced Trimix in other agencies?

At the same tier in TecDiveTools' cross-agency comparison: PSAI Explorer Trimix, SSI XR Hypoxic Trimix, RAID Hypoxic Trimix, PADI TecRec Tec Trimix Diver and IANTD Trimix Diver. They cover comparable training, but each agency sets its own standards, depth limits and certification card, so they are comparable rather than interchangeable — check which one your next course accepts.

PSAI Explorer TrimixSSI XR Hypoxic TrimixRAID Hypoxic TrimixPADI TecRec Tec Trimix DiverIANTD Trimix Diver

Where can I take TDI Advanced Trimix?

73 dive centres and 132 instructors in the TecDiveTools directory teach TDI Advanced Trimix across 7 countries, most in Egypt, the United States, the Philippines and Malta. Each is listed further up this page.

Does the price of TDI Advanced Trimix include gas and equipment?

Not always — it varies by centre. Helium, certification fees, equipment rental and boat or site fees are commonly charged on top of the course price. Each centre's price list on TecDiveTools shows what it notes as included.

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