Technical Diving International

TDI

One of the largest technical training agencies, covering decompression, Trimix, cave, wreck and rebreather pathways.

TDI is among the largest dedicated technical training agencies worldwide and is well represented in Australia, particularly in Victoria, Tasmania, New South Wales and South Australia.

Its pathway runs from Intro to Tech through Advanced Nitrox, Decompression Procedures, Extended Range and Trimix, with parallel routes into cave, advanced wreck and closed-circuit rebreather diving.

For Australian divers, TDI's cave and Trimix programmes are particularly relevant given Mount Gambier and the depth available at Port Phillip Heads and the Ships' Graveyard.

Full name	Technical Diving International
Programs	Intro to Tech · Advanced Nitrox · Decompression Procedures · Extended Range · Trimix · Cavern and Cave Diver · Advanced Wreck · CCR pathways · Sidemount
Strengths	Comprehensive technical range · Strong cave and rebreather programmes · Well established in Australian technical centres · Close integration with SDI recreational training

Verify the specific course, not the logo

A TDI affiliation means the centre can teach TDI courses, not that it teaches all of them. An instructor qualified to teach Advanced Nitrox is not necessarily qualified to teach Trimix or cave.

Always confirm the specific course level, the instructor's own qualification and the centre's gas support before committing to a technical programme.

Courses in the TDI pathway

How each qualification is named under TDI, and what it actually teaches.

Enriched Air Nitrox — Nitrox DiverDiving with elevated oxygen to extend no-decompression limits — the most commonly taken specialty.Wreck Diver — Advanced WreckDiving wrecks safely, and understanding where external touring ends and penetration begins.Cavern Diver — Cavern DiverDiving within the light zone of an overhead environment — the first genuine step into overhead training.Cave Diver — Full Cave DiverFull overhead penetration diving, where direct ascent is not available at any point.Sidemount Diver — Sidemount DiverCarrying cylinders at your sides — redundancy, streamlining and access through restrictions.Advanced Nitrox — Advanced NitroxHigh-oxygen decompression gases and oxygen-clean equipment — not ordinary recreational Nitrox.Decompression Procedures — Decompression ProceduresPlanning and executing dives with a mandatory decompression obligation.Trimix Diver — Trimix DiverAdding helium to manage narcosis, oxygen exposure and gas density at depth.Closed Circuit Rebreather Diver — CCR DiverRecycling breathing gas to extend duration, reduce bubbles and optimise oxygen exposure.

Australian centres with verified TDI affiliation

Only centres where the affiliation is documented are listed. Many more teach this agency's courses without our having verified it.

Dolphin Scuba DivingA Perth business providing training, equipment and service support.Tasmania Tech and Dive CentreThe Tasmanian operation most clearly associated with technical diving services, spanning recreational and technical training with technical gas support.