During the Enriched Air Nitrox 40 Program, you will gain comprehensive knowledge of how oxygen-enriched gas mixtures affect your body and your dive profile. The curriculum focuses on the practical application of nitrox, including the mastery of oxygen analyzers and the calculation of your Maximum Operating Depth for various gas blends. You will also learn to integrate nitrox settings into your dive computer to optimize your decompression limits. This internationally recognized specialty provides you with the skills to safely use nitrox mixes containing up to 40 percent oxygen at dive centers and liveaboards around the world. By mastering these concepts, you ensure a higher level of safety and competence for every future underwater adventure. Upon completion, you will earn an SSI Enriched Air Nitrox 32% or 40% certification.

Build on your technical diving skills and learn to plan and conduct staged-decompression dives in a twinset. On successful completion, the SSI Extended Range certification permits dives to a maximum of 45 metres, using decompression gas mixtures up to 100% oxygen and no more than 25 minutes of accumulated required decompression, with an equally or more qualified buddy.Already certified in SSI XR Nitrox? Your four training dives may count towards Extended Range dives 1–4 when they meet SSI’s credit requirements. That gives you a shorter upgrade route focused on the remaining skills, assessments and two qualifying dives.PrerequisitesYou must be 18 or older, have at least 50 logged dives, and hold Deep Diving and Enriched Air Nitrox 40 certifications, or recognised equivalents. You should be proficient in the twinset configuration you’ll use for training. XR Nitrox certification provides possible dive credit; it does not replace the 50-dive requirement.We’ll complete the required medical screening before training and advise you if physician clearance is needed.Choose your routeFull Extended Range course — four teaching daysTraining begins with equipment configuration, academics, the XR Water Fitness Evaluation and at least two hours of confined-water skills. You’ll complete six open-water training dives: the first two at Markethill Scuba, followed by four dives over two consecutive days at Portroe Dive Centre. The final two dives include staged-decompression training, must total at least 90 minutes, and include at least one dive to 40 metres.Upgrade from XR Nitrox — two teaching daysWe’ll review your XR Nitrox training record and equipment configuration to confirm which dives can be credited. You’ll complete any outstanding Extended Range academic, fitness and confined-water requirements at Markethill, then complete dives 5–6 at Portroe. The upgrade route depends on your previous dives meeting SSI’s credit conditions and your readiness for the final dives.Certification is awarded only after all academic and in-water requirements are met. Additional training may be needed if skills, dive times or conditions do not meet the required standard.