PADI Course
Enriched Air Nitrox
Less nitrogen, longer bottom times — the most popular PADI specialty.
💡Healthcare workers / students / returning students get discounts. WhatsApp for details.
Duration
Half day to 1 day
Max Depth
Max 40 metres (EAN40 limit)
Prerequisite
PADI Open Water Diver or equivalent
Certification
PADI Enriched Air Diver (lifetime cert)
Course Overview
Enriched Air Nitrox (EANx) increases the oxygen percentage in your breathing gas — typically from 21% in regular air to 32% or 36% — which proportionally reduces nitrogen. The direct result: at the same depth, you absorb less nitrogen, allowing longer no-decompression bottom times.
This is why Nitrox is the most popular PADI specialty worldwide. For anyone planning multi-dive days (2-4 dives in a day, or multi-day consecutive diving trips), it meaningfully extends bottom time and shortens surface intervals.
The course is primarily theory-based: oxygen toxicity principles and risks, gas analysis methodology, Maximum Operating Depth (MOD) calculations for different Nitrox blends, and Nitrox dive planning. You'll practice actual gas analysis — so you know how to analyze your own cylinder before every dive.
Optional: 2 Nitrox dives after the theory, to experience breathing Nitrox on a real dive.
Who is this course for?
An honest look at who this course is — and isn't — for.
This course is for you if…
- OW or AOW divers planning multi-day liveaboard or resort dive trips (Maldives, Palau, Philippines)
- Regular Fun Divers who want longer bottom times
- Considering the technical diving path (Nitrox is a foundational technical skill)
- Want to understand gas mixing principles and learn more dive science
- Planning 3-4 dives per day and want shorter surface intervals
Maybe not for you if…
- Divers who only do occasional single dives (Nitrox benefits are minimal with infrequent diving)
- Anyone unwilling to perform gas analysis before every Nitrox dive (required procedure)
- Very new divers still building foundational skills
Course Schedule
Actual scheduling adapts to weather and your progress.
Phase 1 — Theory
Nitrox principles and safety
Cover core Nitrox knowledge: oxygen toxicity mechanisms and symptoms, Maximum Operating Depth (MOD) for different oxygen concentrations, Nitrox dive planning and logging, and special equipment considerations. Complete via PADI online knowledge development; class time focuses on discussion and questions.
In addition to the online PADI eLearning, theory includes in-person discussion and Q&A. Conducted in Tsim Sha Tsui by default. If you can't attend in person, sessions can be moved to Zoom or arranged at a designated café.
Phase 2 — Practical exercise
Gas analysis hands-on practice
Use an oxygen analyzer to analyze actual Nitrox cylinders, calculate and confirm MOD, and complete Nitrox use documentation. This is the mandatory procedure before every Nitrox dive — you need to do it hands-on to truly master it.
Phase 3 — Optional dives
2 Nitrox dives (optional)
Optional: 2 open-water dives in Sai Kung using Nitrox cylinders. Apply Nitrox planning and documentation in a real dive. Experience the actual feel of diving on Nitrox and observe the difference in bottom time.
What's included?
All costs transparent — no hidden fees.
Included
- PADI Nitrox online knowledge development account
- Full PADI-certified instructor guidance
- Oxygen analyzer use and guidance
- PADI Enriched Air Diver certification fee
- Optional dives (if selected): equipment rental, boat fees, insurance
Not included
- Nitrox cylinder costs for optional dives (slightly more than air)
- Lunch (if optional dives included)
Healthcare workers and students get an additional HK$200 off with valid ID
Safety is non-negotiable
The core safety concept in Nitrox is oxygen toxicity management. Higher oxygen percentages mean shallower Maximum Operating Depths (MOD). EAN32 limits you to 34 metres; EAN36 to 29 metres. Exceeding MOD risks central nervous system oxygen toxicity, which can cause convulsions underwater — a serious and potentially fatal situation.
The course's primary focus is ensuring you fully understand and internalize MOD awareness, and develop the habit of analyzing your cylinder and confirming MOD before every Nitrox dive. This procedure may seem laborious, but it's the fundamental step that keeps you safe — it cannot be skipped.
Before every Nitrox dive: analyze oxygen concentration with an analyzer, calculate and record MOD, and set your dive computer to Nitrox mode. All three steps, every time.
Frequently Asked Questions
The most common questions students ask about this course.
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