When you complete your open water scuba course, the maximum depth for your dives is 18 meters. Let me explain what happens, and what does not happen when you nevertheless dive deeper!
Firstly, what will not happen is that the scuba police will ticket or arrest you. The reason for this is that there is no such thing as the scuba police! Legally, you are not prevented from doing underwater whatever you want to do, in all but a few countries. In the Maldives you aren’t allowed to dive deeper than 30 meters, although I don’t know how this is enforced (I believe it’s up to the dive shops). In the Philippines, there is certainly no one checking your dive computer for maximum depth when you return to dry land after a dive.
BUT it’s still not a good idea to dive beyond your training, not for legal reasons, but quite simply because it’s dangerous. As a beginner diver you are lacking the skills to venture deeper. What is different at depth, as compared to shallow water? A few things are!
Immediate direct ascent is not an option anymore. When you are eight meters deep and encounter any kind of problem you can almost certainly ascend within a minute. You even practice that during your PADI Open Water course – it’s the controlled emergency swimming ascent. That does not work from 30 meters – you need to be able to prevent problems, or solve them if they occur at depth.
You also need to be more careful with your gas management. When you dive in 30 meters, the ambient pressure is 4 bar … 4 times the pressure at the surface. This means that you take in 4 times as much air per breath as you would at the surface, and still 2 times more than during a dive to 10 meters. If you don’t take this increased air use into account and check your pressure gauge more often, you could run into a nasty surprise. You don’t want to find yourself low on air, while still at depth. It’s easy for an experienced diver to manage his or her breathing gas, but a beginner can be quite surprised by the quick drop of the needle on the gauge!
And, your body will take up much more nitrogen. This means that your time at depth is limited – once you have taken up a certain amount you need to turn your dive. The alternative is to do a decompression stop, but as recreational divers we want to avoid that. Hence, we need to bring a dive computer and watch the “no decompression time” it shows us. Again, this is not a terribly difficult task, but a beginner diver still needs to concentrate on doing it well. And all of that is made harder by the dreaded …
… nitrogen narcosis. Yes, the regular, old-fashioned nitrogen which makes up 79% of the atmosphere becomes a dissociative drug when breathed under high pressure. Not unpleasant in principle, BUT it’s simply not a good idea to be too dazed when in a potentially dangerous situation, during a deep dive. Short term memory impairment, anxiety or euphoria and tunnel vision are common effects of nitrogen narcosis. If things get too bad, you simply need to dive a bit shallower. But: I wrote a blog post for PADI’s tech site explaining that narcosis does not go away right away after ascending.
How can you learn to cope with these issues so that you are able to safely dive deeper? Take a course – At Salaya we have three instructors, Laura, Marc and Klaus, who can each teach you how to dive deeper – in the PADI Deep Diver Specialty course. The course encompasses four dives, and you will learn to dive to 30 to 40 meters safely. Dauin and Apo island have lots of dive sites with interesting animals to observe at depth.
PADI is promoting the Deep Diver Specialty course in the first quarter of 2018 as the “Specialty of the Quarter”. That means you’ll get 10% off the regular course price at Salaya, and 15% off if you take both this course as well as the other Specialty of the Quarter, Enriched Air Diver (see last week’s blog). The Deep Diver Specialty can also serve as a stepping stone into tec diving.