Deep air diving to 55 metres with staged decompression — no helium required. For qualified technical divers in locations where helium access is limited, or those who want to maximise their depth capability on air before moving into trimix.
The TDI Extended Range Diver course teaches the techniques, equipment requirements, and hazards of deep air diving to 55 metres — with staged decompression using nitrox or oxygen on the ascent. It's designed for already-qualified technical divers who want to extend their depth capability without helium, whether due to limited gas availability at their home destination or as a deliberate step in their technical development.
Deep air at 55 metres carries a significant narcosis load and requires careful planning, disciplined execution, and a thorough understanding of the physiology involved. This isn't a course for divers new to technical diving — you'll need Advanced Nitrox and Decompression Procedures already under your belt, plus 100 logged dives with 25 deeper than 30 metres. The course builds directly on that foundation.
Over the course of training you'll plan and execute dives to the target depth on real sites, manage two stage cylinders underwater (either two decompression gases or one deco and additional bottom gas), deploy lift bags and ascent reels, and demonstrate the emergency procedures that deep air diving demands. Malta's clear water and accessible deep sites make it an excellent location for this training — the visibility means you can see exactly what you and your team are doing at depth.
Upon completion, Extended Range certification also qualifies you to enrol in TDI Advanced Wreck, TDI Trimix, and TDI Advanced Trimix — making it a versatile stepping stone within the technical diving pathway.
Not sure if Extended Range is the right next step for you, or whether Trimix Diver makes more sense given your goals? Get in touch and we'll talk it through — it depends on where you want to dive and what helium availability looks like for you.
Extended Range certification qualifies you for depths to 55 metres on air with staged decompression — and unlocks enrolment in TDI Advanced Wreck, TDI Trimix Diver, and TDI Advanced Trimix. For divers focused on destinations where helium isn't readily available, it's a highly practical qualification. In Malta, where helium is available, it works well alongside the trimix pathway as an additional depth credential.