Is Nitrox Worth It? Cost and When It Pays Off

Whether nitrox is worth it depends on how you dive, not on the gas. If you do two or three dives a day for several days, as on a Sodwana trip, it buys longer no-stop time and shorter waits between dives for R3,200 once and about R130 to R150 more per fill. If you dive one shallow tank on a Saturday, you'd barely notice it. This guide answers the questions South African divers ask before they sign up.

The physics of why it works, and the depth limit it adds, is in our guide to what nitrox is and why it doesn't let you dive deeper. This one is about the decision.

Is nitrox worth it for a recreational diver?

It's worth it when your dives run into the no-stop limit or you stack several dives in a day. It isn't worth much when you dive once, shallow, with plenty of gas and time to spare.

The gain is nitrogen you don't absorb. At 18 metres the PADI Recreational Dive Planner gives 56 minutes on air and 95 on EAN32. Between dives the same effect shortens the surface interval you need before the next one. On a day with three boat dives, that's the difference between waiting on the beach and diving.

Be realistic about the rest. Many divers expect to feel less tired. Controlled studies haven't found it, and our other guide covers that research. Nitrox also doesn't make a cylinder last longer. If you dive your air limits on nitrox instead, the extra margin is real, and our nitrox guide covers the 2016 bubble trial.

What does a nitrox course cost in South Africa?

At Scuba Evolution the Nitrox Course (PADI Enriched Air Diver) costs R3,200. Prices at other shops differ, so compare what's included. Ours covers the PADI eLearning, the practical session with an instructor and all scuba equipment for the duration of the course.

There are no open water training dives. You work through the eLearning in your own time, then spend a session with an instructor analysing a cylinder, logging the blend and setting your dive computer. PADI says the course takes a few hours, and most divers finish within a day.

You need to be a certified Open Water diver, or enrol in the Open Water course and the nitrox course together. The minimum age is 12, and divers aged 12 to 14 earn a Junior Enriched Air Diver certification with a maximum depth of 21 metres.

How much does a nitrox fill cost?

A nitrox fill at our shop in Glenvista is R280, including VAT. An air fill to 232 bar is R130 and to 300 bar is R150, so nitrox costs R130 to R150 more per cylinder. We analyse the mix before the cylinder leaves the counter and we both sign the fill log. You then analyse it again yourself before the dive. Details are on the air and nitrox fills page.

On a dive trip, operators set their own nitrox prices, and some don't offer it at all. Ask what's included before you book, in the same way you'd ask about kit and launch fees.

Nitrox or air at Sodwana?

Sodwana is where nitrox helps most often. Two-Mile Reef runs from about 9 to 34 metres, and a typical trip is two or three boat dives a day for several days, which is the pattern that eats into no-stop time on air.

Two things to plan. First, your depth limit drops: EAN32 reaches its 1.4 bar ceiling at about 33.8 metres, so plan to your mix, not to the reef. Second, check the mix yourself on the boat before you dive and set your computer to the number you measure. A computer left on its air setting gives you the wrong oxygen exposure.

You don't need nitrox to dive Sodwana. Plenty of divers go on air and do well. If you're already doing repetitive diving, it takes pressure off the clock. Our guide to first ocean dives at Sodwana, Aliwal Shoal and Ponta covers the rest of the trip planning.

Should you do the nitrox course straight after Open Water?

It's a good time, because the course adds planning and gas checks rather than new in-water skills. You can enrol in both together with the Open Water + Enriched Air combo. The step after that for most divers is Advanced Open Water (R5,000), which takes your limit to 30 metres, and the order is explained in our guide to PADI courses in order.

If you only dive inland a few times a year, wait until a trip or a run of repetitive dives makes it useful. The certification doesn't expire, and it counts towards Master Scuba Diver.

What are the risks of nitrox?

The risk nitrox adds is oxygen toxicity below your mix's maximum depth, which is why the course teaches you to analyse the cylinder, work out your limit and set your computer. Nitrox doesn't remove the risk of decompression sickness either, and it won't help with narcosis. If you have symptoms after a dive, call the DAN Southern Africa emergency line on +27 82 810 6010.

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Frequently Asked Questions

Is nitrox worth it for a recreational diver?
It's worth it for repetitive diving and trips with several dives a day, where it lengthens no-stop time and shortens surface intervals. For a single shallow dive the benefit is small. It doesn't make a cylinder last longer or remove the risk of decompression sickness.

How much does a nitrox course cost in South Africa?
The Scuba Evolution Nitrox Course (PADI Enriched Air Diver) costs R3,200, including eLearning, a practical session and equipment for the course. There are no open water dives. PADI says the course takes a few hours.

How much is a nitrox fill?
A nitrox fill at Scuba Evolution is R280 including VAT, against R130 for an air fill to 232 bar and R150 to 300 bar.

Do you need nitrox to dive Sodwana?
No. Many divers use air. Nitrox helps on days with two or three boat dives, and it lowers your depth limit to about 34 metres on EAN32.

Can you do the nitrox course with Open Water?
Yes. You can enrol in the PADI Open Water Diver course and the Enriched Air Diver course together, so your first certified dives can be on nitrox.

What's the minimum age for nitrox?
12. Divers aged 12 to 14 earn a Junior Enriched Air Diver certification and dive to a maximum of 21 metres.

This is general information, not a substitute for dive training, a dive medical or advice from a doctor trained in dive medicine. In an emergency, contact DAN Southern Africa on +27 82 810 6010.

Reviewed November 2026. Devon Ford runs Scuba Evolution, a PADI 5 Star Dive Centre in Glenvista, Johannesburg.