SSI Enriched Air Nitrox

Enriched Air Nitrox swaps the 21% oxygen in regular air for a richer blend — usually 32%. Less nitrogen per breath means less nitrogen loading per dive, which shows up as longer no-decompression limits and shorter mandatory surface intervals, dive after dive.

What it actually changes

Nitrox doesn’t let you dive deeper — if anything, it narrows your depth range. The extra oxygen turns toxic sooner than at ambient-air ratios, so EAN32 brings the maximum operating depth down to roughly 34 metres, and EAN36 to roughly 29 metres. Both are well inside the range of Gili Air’s reef sites, so the trade-off rarely costs you anything here.

What it buys you instead is time. A diver on EAN32 at 18 metres gets meaningfully more no-decompression time than the same diver on air, and surfaces with a lower nitrogen load — exactly where it matters on a day with two or three dives back to back, or across a multi-day trip.

The course

One day. Theory covers how nitrogen loading actually works, how to calculate your own maximum operating depth for a given blend, and how to analyse a tank yourself before every dive — a habit every nitrox diver keeps for life; never trust a fill you didn’t personally check. Then two open-water dives breathing nitrox, so you leave having actually read your dive computer in nitrox mode, not just holding a card.

Already comfortable with the theory, or tight on time? We also run a theory-only certification — same card, no open-water dives required.

Who it’s for

Anyone doing more than one dive a day, which on Gili Air is most of our fun-diving guests. If you’re here for a week doing two dives most mornings, Nitrox is the specialty most divers notice by day three or four — less residual nitrogen, less of that flat, tired feeling after a run of repetitive dives.

It pairs naturally with Advanced Open Water, and counts as one of the three specialties toward SSI’s Master Diver rating alongside Deep Diver, Wreck, Drift and the rest.