What Diver Does Not Want A Longer Bottom Time Right? No?

Let us ask you this – Have you ever been slowly absorbed into the beautiful underwater world while diving and is so amazed by the show that the marine life put together for you and oops, it’s time to ascend. When you’re not ready to leave the dive site yet!

Or, how about this? Hovering over a reef, camera ready in hand, head look up – you see the Manta ray that you’ve been looking for the past half hour. Started screaming through your regulator with joy and is swimming towards your target but wait, your dive computer suddenly went BEEP BEEP BEEP, indicating that you’re going to exceed the no decompression limits and you have no choice but to ascend without a great shot of the Manta ray!


Then, what do you think is the key of it? Yes, you got it, NITROX!! Or another term that is commonly used is known as enriched air.



As human beings, we are always breathing a Nitrogen/Oxygen mix. Right now, you are currently breathing air – which is made up of approx. 79% of Nitrogen and 21% Oxygen. Nitrogen is a relatively inert gas and does not affect us until we are underwater.

Now, let us test you a little! From what you had learnt during your open water diver course, is too much Nitrogen being loaded into our body a good or a bad thing? There you go, yes of course! In order to avoid the negative effects of having excess Nitrogen loaded into the body, divers are to ascend slowly and to make safety stops. They are also required to follow the recommended surface intervals before going for their next dive.

Thus, when using nitrox (enriched air) with proper precautions, it is a different Nitrogen/Oxygen mix with Oxygen higher than 21% and reduced Nitrogen. By reducing the percentage of Nitrogen, it means lesser Nitrogen intake and what does it implies? You can safely extend your bottom time underwater and also shorten your surface intervals between two dives due to lesser Nitrogen being absorbed! What diver does not want a longer bottom time right!?



However, it is important to know the disadvantages of using Nitrox to dive! Since the breathing gas mix has a higher percentage of Oxygen, there is a risk where divers can get Oxygen toxicity. In fact, Oxygen is toxic at certain levels and divers do need to monitor both their depth and the total exposure to Oxygen over a number of dives. One thing, don’t get misled into thinking that diving with Nitrox allows divers to go deeper! That’s totally totally wrong! The truth is, the deeper you go, the higher the oxygen levels and the higher the risk you put yourself in getting CNS Oxygen toxicity.

Also, Oxygen does not burn but high Oxygen levels in the gas mix also increases flammability. How are we going to avoid this? Remember to handle and clean the Nitrox tanks, regulator and valves with extreme care in order to avoid explosions! Make sure that any equipment that comes in contact with pure Oxygen must be ‘Oxygen clean’ which means to use special lubricants.

Lastly, do make it your responsibility to personally analyze the gas mix in the Nitrox tank using an Oxygen analyzer if you’re doing Nitrox diving!



So, what are you waiting for? Sign up the Nitrox course with us now that just takes an evening theory to complete and be an enriched air diver! Yay!


If you’re interested, we do have a class coming up soon! It will be on 20 Jan starting at 7pm. Either email us at [email protected] or ring us up at 6557 2705 to book it.

See you divers!


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