NITROX

The Nitrox specialty at Arrecifal can be completed in a single day, and it's one of the few courses that doesn't require open-water dives — the core content is academic and pre-dive planning, with the optional dive component available for those who want it. The practical payoff is real: Nitrox mixes of up to 40% oxygen extend no-decompression limits compared to air, reduce surface intervals between dives, and increase the safety margin on repetitive dive days.

For divers on a multi-day schedule at El Hierro — doing two dives a day across three or four days — the arithmetic adds up quickly. Longer no-deco limits mean more bottom time on each dive. Shorter surface intervals mean the second dive of the day can start sooner. Arrecifal runs two dives per morning, so having Nitrox certification lets you get more out of each session, especially on deeper sites where air-based limits compress fast.

The course teaches planning and safe use of enriched air mixes up to 40% oxygen: how to analyse the mix, set your dive computer, calculate maximum operating depth, and understand the physiological differences from standard air. These are tools you then carry to every dive you do — not just on El Hierro, but anywhere in the world where Nitrox is offered.

Prerequisite is Open Water Diver or equivalent from a recognised agency. Minimum age is 10 years. Given the planning-heavy nature of the course, it pairs well with any multi-day diving programme at Arrecifal, and the centre can incorporate it alongside guided dives rather than consuming a separate day entirely.