The bridge between standard trimix and unlimited depths. 75 metres, high-helium blends, extended decompression, and access to wrecks like HMS Southwold at 73m — historically significant dives that require serious preparation.
Trimix 75m sits between standard Trimix Diver (60m) and Advanced Trimix (no limit). It's a deliberate stepping stone — extending your depth range to 75 metres without jumping straight to unlimited depths. For many divers this is the sweet spot: it opens up wrecks like HMS Southwold at 73m and Le Polynesien at 65m with proper bottom time, without the complexity and cost of going beyond 80 metres.
HMS Southwold is a Hunt-class destroyer that went down in 1942 during Operation Pedestal. She lies in two sections at around 73 metres off Malta's east coast, and she's one of the most historically significant wrecks in the Mediterranean. At standard Trimix depth (60m) you're looking at her from above. At Trimix 75m you're on her, with meaningful time to take it in.
The course runs 6–8 days because we're dealing with extended decompression obligations — deco stops that can run 60+ minutes — and high-helium blends that need careful planning. Gas density becomes a real consideration at this depth. Equivalent narcotic depth (END) matters. The number of cylinders you're carrying matters. We work through all of it methodically before we get in the water.
You'll need a solid foundation in trimix diving before this course makes sense. The prerequisite is Trimix Diver and 150 logged dives — not as boxes to tick, but because the experience changes how you process what we're covering. Divers who come in with recent trimix dives and good decompression discipline get far more out of the course than those who haven't touched trimix in two years.
This course builds the skills and discipline you'll need if you decide to pursue Advanced Trimix later. But plenty of divers stop here — 75 metres gives you access to the vast majority of diveable wrecks worldwide, and it's a depth you can plan and execute conservatively without the logistics and cost spiralling.
Le Polynesien at 65m and HMS Southwold at 73m are bucket-list wrecks. This course opens them both up with the depth range and decompression training to dive them properly — not just reach them, but actually experience them.
Trimix 75m certification gives you access to Malta's deepest accessible wrecks — HMS Southwold (73m), Le Polynesien (65m), ORP Kujawiak (65m) — with the skills and depth rating to dive them conservatively. It's also the logical stepping stone to Advanced Trimix, which removes the depth limit entirely and opens wrecks beyond 80 metres.