Deep Specialty course

When I started diving, I did not like deep dives. I hated the boat rides to get to the dive sites – the combination of a vivid imagination and a few scary experiences makes me something of a tense sailor. I also get seasick when the boat stops and the sea is choppy – swell plus motor fumes is a bad combination!

Time has improved the situation. I’m a much more relaxed boat passenger than I was a year ago. I make sure to travel with skippers I trust. I make sure I’m seated near the back of the boat (for bumpiness), and I wedge my feet into the footstraps and hold on to the ropes. I’ve been lost at sea for a little while, and while unpleasant, it wasn’t as scary as I thought it would be.

I’ve also conquered my fear of deep water. Friday’s dive in Smitswinkel Bay was the first deep dive that I’ve been totally relaxed about, before and during. I’ve learned to trust my equipment, and to trust my buddy. I know how I feel at 30 metres down (sharp as a stack of wet newspapers), and I consciously relax. I have breathed off Tony’s octo at the bottom of the ocean (I sucked air prodigiously on my first couple of deep dives) and both of us survived. The apparent viscosity of the water at depth (like swimming through honey) doesn’t surprise me any more, and I know not to over-exert. My buoyancy has improved greatly and I don’t get panicky when I have to inject several squirts of air into my BCD to slow my descent.

Deep dives are awesome. It’s incredible to see the colours come to life when you shine a torch on things, or fire off a camera flash. It’s also thrilling to be able to explore a part of the ocean that is completely inaccessible in the normal course of things.

I also love safety stops. I love floating in midwater, seeing everyone’s bubbles around me, and feeling like an astronaut. We did a dive on the SAS Transvaal in incredibly visibility, and this video Tony took on the safety stop captures the feeling of weightlessness and space.

[youtube=http://www.youtube.com/watch?v=q-raFP0oP3A&w=540]

The only frustration to me is how short the dives are. Because of the increased pressure at depth, you breathe a LOT more air out of your cylinder with each breath than you do on a shallow dive. At 40 metres, each breath consumes five times more air than at the surface. You also have to watch your dive time to avoid hitting the RDP limits at depth. A Nitrox course comes in handy here… But it seems that practice, and improved diving technique, are the key elements to improving air consumption, dive time and enjoyment of the whole experience.

The theory aspect of the course covers dive techniques related to drift and wall dives, decompression sickness and how to avoid it, safety stops and one or two other matters such as photography at depth. The skills required on the dives mainly relate to safety stops, different types of ascent and descent (with and without a reference line), and a little bit of navigation. It gives me great confidence to know that I am now certified to 40 metres, although, as the manual points out, 30 metres seems to be the “optimum depth” for the kind of scuba diving I enjoy.

Reef rules

Please remember, coral reefs are delicate, home to creatures we are privileged to visit and need to be respected. Control your buoyancy, tuck in your gauges, octos and torches.

Some of the corals have taken hundreds of years to grow to their current size. A careless fin kick could destroy decades of growth.

Don’t touch anything – coral reefs are a delicate ecosystem, and you can transport algae and other organisms on your hands from one coral to the other. This isn’t a good thing – it’s the equivalent of coughing on someone when you have a cold!

No touching! I am looking at you!
No touching! I am looking at you!

And finally…

Do not go deeper than the bottom!

Do not bite anything that bites you!

If your buddy is bitten by anything he should not be touching please take a picture for us to use in issuing beer fines!

Why it’s a good idea to carry an SMB

When I met Tony he was living in Mozambique, and when his visa ended he moved to Durban. Around that time we had decided we quite enjoyed each other’s company, so I flew up every second weekend to visit him. He was working at Calypso Dive and Adventure Centre at uShaka Marine World as an Instructor and Divemaster, so I tagged along on dives on the Saturday mornings I was in town. I was a fairly new diver at the time (it was September 2009).

It was the first time I’d come up to Durban to see him, and he had a student who had to do a deep dive on the Saturday morning. The boat was heading out to the Coopers Lighthouse wreck, a mysterious ship lying in 24-32 metres of water whose identity is not certain. Some people think it’s an old whaler, but there are several theories as to its origin. The wreck is thought to be about 100 years old and situated in line with the Cooper Lighthouse on the Bluff.

The rubber duck left the beach at 0700. The sea was looking quite bumpy, and the boat ride wasn’t great. I am not the best sailor, but as long as the boat is moving I’m fine. It’s about a 25 minute ride through shipping lanes, south of Durban harbour.

There was a howling current when we arrived at the site, and while we kitted up on the boat we drifted some way from the shot line hooked to the wreck. The sea was horrible – I alternated vomiting over the side (so embarrassing) with doing up clips on my BCD! Once we were ready, the skipper circled round and dropped us close to the shot line, but on the wrong side – so the current was taking us away from the line rather than towards it. I was with Tony, and his student – who was on the other side of the boat – had managed to get to the shot line and was holding on for dear life. In the current, his body was horizontal, like a flag in a strong wind.

Tony and I swam and swam, for what felt like an hour. We were swimming into the current at about 10 metres depth, but I think we were either standing still or moving backwards (it must have looked quite funny, if you were in that sort of mood). We could see Tony’s student, and we could see the shot line ahead of us, and then it just seemed to vanish. By that time the student had joined us, and the current had taken us out of sight of the line.

I wasn’t quite sure what we would do at that point, but Tony had a plan, which he explained to me later, on dry land. We descended to about 20 metres, and stayed there for about 20 minutes. The three of us were hanging in the blue ocean – no sign of the bottom – surrounded by shoals of fish. We could have surfaced immediately when we lost the shot line, but then we’d have had to spend the duration of the dive sitting on the boat, which was being tossed about like a cork. (I’d already demonstrated low tolerance for this kind of activity by chumming the local fish life while kitting up.) That’s if the boat had even found us – the skipper wouldn’t be expecting divers to surface after only ten minutes, and the conditions were not conducive to him spotting us as soon as we surfaced.

After about 20 minutes we began our ascent, doing a safety stop at 5 metres with an SMB deployed. When we reached the surface, the sea was mountainous. There was no sign of the boat, and even if it had been five metres away from us we’d have struggled to see it because of the size of the waves. Tony clipped our BCDs together so that we would drift more slowly (larger surface area to offer resistance to the current), and told me to keep my regulator in my mouth becuase the waves were so big. (It was on this dive that I discovered that you can vomit through a regulator… useful fact to keep in mind…)

Then we waited. The bright orange SMB stuck up between us, and in between gags I scanned the horizon (which was not very large, thanks to the waves) for the boat. The three of us floated there for 55 minutes before the boat found us. After being hauled aboard like a drowned rat I heaved over the side for good measure and then concentrated on my lollipop.

The skipper told Tony he’d been driving around looking for us, cursing Tony for not having an SMB deployed. We did – but the waves were so big that the boat was practically on top of us before it could be seen. If we hadn’t had an SMB, I very much doubt they would have found us without the aid of the NSRI.

Reels and surface marker buoy (SMB)
Different sized reels and surface marker buoys (SMB)

For the uninitiated, SMB stands for Surface Marker Buoy. They’re generally tubes of orange, red or yellow plastic, that you inflate by inserting your octo or regulator at the bottom, and purging it. It’s generally considered good practice to deploy an SMB at the safety stop when you’re on a boat dive – it warns other boats of your presence, signals that you’re ok, and gives your skipper an indication of where to come and fetch you.

If you get lost on the surface, a SMB is essential. You’re not very visible dressed from head to toe in black, and that orange tube might be the only difference between a very long time drifting on the surface, and a quick rescue. They fold up really small, and with a little practice are very straightforward to deploy. If you’re diving off a boat, or in an unfamiliar location, make sure you pack your SMB.

FAQ: Do I need to be a good swimmer in order to scuba dive?

You don’t need to be an Olympic swimmer in order to learn to scuba dive. Scuba diving isn’t about covering big distances or swimming really fast. In fact, we take great care not to over-exert ourselves in the water, and if you swim too fast you won’t see a thing! Also, divers wear fins, which add a lot of power to your kick stroke, and wetsuits and BCDs, which assist with buoyancy.

However, you do need to be at least comfortable in the water in order to become a scuba diver. If you’re absolutely terrified of water and struggle to take a shower without a lifeguard on standby, scuba diving is not the sport for you. If you can’t swim at all, you do need to learn to swim before you learn to dive. If you’re a half way ok swimmer who can hold your own in your pool at home (but not necessarily swim the English Channel), then let’s talk!

There are swimming tests for the various courses (the precise name of the skills being tested is watermanship). For Open Water, you have to do the following, either in a swimsuit or wearing a wetsuit and weighted for neutral buoyancy (i.e. wearing a weight belt):

  • swim 200 metres continuously without any swim aids,
  • OR swim 300 metres continuously wearing fins, snorkel and mask ;
  • float unassisted in water too deep to stand in, for 10 minutes.

The Divemaster course requires the following:

  • swim 400 metres non-stop with no swimming aids;
  • swim 800 metres non-stop, face in the water, wearing mask, snorkel and fins, with hands tucked in;
  • tow or push another diver for 100 metres in full gear, non-stop;
  • tread water for 15 minutes in water too deep to stand in, hands out of the water for the last 2 minutes.

At Open Water level, these swims are not timed.  The Divemaster and Instructor swims are timed. You can use whatever stroke you want, but doggy paddle may get tiring! The swims are very important to confirm that you have basic water skills and can take care of yourself (and others, at DM and Instructor level).

If you’re a decent swimmer already, improving your swimming fitness, stamina and technique will definitely improve the quality of your dives. Not having to think about your position and attitude in the water will enable you to focus on the other things around you, and get more out of the experience. Developing your swimming muscles (that’s almost all your muscles!) and your cardiovascular endurance in the pool will make diving feel a lot less physically strenuous, and you’ll be far more relaxed knowing that your body is in a condition to handle the sport with no strain at all.

Surface time
You should be comfortable on the surface as well as below the surface.

Finally, being a confident swimmer will make you a more confident scuba diver. While we try not to rush on dives, you never know when a situation will arise that will require you to swim towards or away from something quickly. If you do boat dives, you’ll need to float on the surface at the start and/or end of the dive, waiting for the other divers to gather together, or for the boat to pick you up. Strong swimming technique and developed muscles will help you in both these situations. Basic swimming skills should be part of your arsenal as a fully prepared and competent scuba diver.

If you are in need of swimming lessons – whether it’s to start from scratch or improve your stroke, contact Swimlab, run by Hilton and Wayne Slack, at the Wynberg Military Base swimming pool and in gyms around Cape Town. They offer swimming lessons, coaching, training for high performance swimmers, and even sell swimming gear.

Oral inflation

As I have mentioned before, problems arise when we don’t follow our training. I was working at a busy resort as skipper, Divemaster and Instructor. On a busy day I would kit up at 6.00am, launch the boat, dive, hit the beach to collect the next group, quickly change cylinders and head straight back out again to dive, sometimes doing four or five dives a day. We would only be done by early evening so there was no time for kit maintenance.

I had a problem with my inflator during the last dive of the day and quickly replaced it with a spare from my dusty tool kit late in the evening. Being too tired to fetch a cylinder I did not test it (mistake number one). The following morning I was distracted whilst kitting up and did not test it (mistake number two). The first dive of the day was to 40 metres. Being skipper and Divemaster meant I did not have too much time on the boat for a buddy check (mistake number three).

Half way down to the reef I intended slowing my descent and found my inflator was not working. Ah, no problem, I teach people how to orally inflate their BCD every time I have a student so I was not concerned. What I had forgotten was the pressure exerted at 40 metres on the bladder of your BCD is way more than you can imagine and oral inflation at that depth is a lot more difficult than it is at 18 metres. Instead of a few small breaths to reduce my descent it took a good eight or ten and by this time I was ready to bounce off the bottom.

Diving at Ponta do Ouro
Diving at Ponta do Ouro

The moral of my story: remember to always do a buddy check even if you have to do it on yourself. Don’t skip this step! And don’t change anything on your kit without testing it prior to dropping off a boat.

Out of air!

Out of air emergencies should not happen. Diving safely includes being sure that you have checked everything yourself, doing a buddy check and diving within your own personal limits. Always avoid making too many changes to your gear configuration and don’t test more than one new item at a time unless you are in shallow, confined water.

Most incidents are a culmination of several small mishaps and would most likely not have occurred had just one error being omitted. The other issue to be aware of is trusting your training and avoid thinking you know better. Here’s why…

I was diving in Mozambique, did a backward roll, and a negative entry (that’s when you don’t hang around on the surface with an inflated BCD, but start your descent immediately). Now, doing negative entries is not ideal, but the surface current was strong, we were diving a small reef and I wanted to get down quickly. So after the roll I finned down head first as fast as I could, without a buddy… Mistakes number one and two.

At 18 meters I found breathing to be difficult. Having just over-exerted myself I stopped to catch my breath but found as I reached the end of my breath my regulator stopped giving me air. Slow breaths were okay but it would not deliver what I needed. I instinctively looked at my pressure gauge, plenty of air in the cylinder but the needle dropped off as I took a deep breath.

“AHA my cylinder is not all the way open,” I thought so I reached up to try and check. It felt open, but convinced I was not doing it properly I took my kit off, held it in front of me and checked. The cylinder was all the way open, and now suddenly I was not getting air at all. I swam to the surface, slowing at about 8 metres to grab a few breaths from a buddy pair descending slowly.

On the surface I signaled the boat and whilst remaining in the water had the top man change my regulators – mistake number three. Straight back down to 18 metres I went, breathing normally and as soon as I turned face down to scan the sea for the group I ran out of air again. Back to the surface as fast as possible! A CESA from 18 metres is relatively difficult once you are stressed and short of breath from over exertion.

On the second descent logic was telling me the problem had to be my cylinder, but arguing with myself I dismissed this as I had serviced my cylinder less than three months prior to this and felt it could not possibly be at fault.

Back in camp I stripped my pillar valve and found it to be blocked with rust and sand. How could this be?

After investigating it turns out the cylinder was dropped from a vehicle a few weeks before this by the compressor operator. The pillar valve was damaged, so they drained it in a hurry, causing condensation, dropped it again in the sand, rinsed it with the water used for cooling cylinders whilst filling (salty water), emptied the water out, replaced the pillar valve with a used one, without a snorkel (a small pipe that runs from the bottom of the pillar valve into the cylinder). I got it back full of air unaware of the incident. The salty water inside rusted the cylinder, the absence of a snorkel meant that every time I was pointed head down the scales inside slowly drifted into the pillar valve until it was totally blocked.

It is not unusual for a little spot of rust to develop in a cylinder. It’s not ideal but it won’t kill you. However a snorkel ensures the pillar valve is supplied with clean air and the scales are kept out – in my situation in Mozambique, the scales would have settled around the top of the snorkel where it attaches to the pillar valve, instead of blocking the valve completely. The other end of the snorkel would have been a bit further into the cylinder, drawing clean air. When I took my cylinders to Orca Industries recently for their annual maintenance, I was very impressed that they insisted on checking each one for snorkels, and fitting them if they were absent.

Breathing underwater

Most divers ask “how long will my air last?” There are several variables to this but primary factors are how much air you start with, the depth you intend diving to, and your rate of consumption.

Body size is important, and activity underwater and stress levels are also factors. Fitness is not necessarily an huge factor. An unfit overweight diver that moves slowly in a relaxed manner will consume less air than an elite athlete with a high stress level finning inefficiently.

A 12 litre cylinder filled to 200 bar will have 2400 litres of air. If your breathing rate is 20 litres a minute on the surface you could use the cylinder for 120 minutes. The same cylinder at 30 metres will only last 30 minutes.

Cylinders
If you decide to purchase your own cylinder, it’s critical to maintain it

The technical jargon to work out your predicted air consumption per minute is as follows:

The volume of the tank is divided by the breathing rate multiplied by the absolute pressure of the depth at which it is breathed.

Afterwards, you can calculate your realised or actual breathing rate for a particular dive. Take the amount of air you consumed on the dive in bar, and work out how many litres you used using the above information. You can work out how many litres of air you used per minute by dividing the number of litres by the dive time. You can track your air consumption, and tie it to a variety of factors – how you felt on the day, your weighting, how your gear was set up, and of course depth – if you keep proper records in your logbook for each dive.

Finning

Not getting anywhere

Often divers find that the hi-tech latest fins they bought for a packet are not giving them the pleasure and speed they thought. The slightest current has them finning as fast as possible, consuming air rapidly and not keeping up with the other divers.

A decent pair of fins allows you to use your most powerful muscle, your thigh muscles. If you fin like you ride a bicycle you will go nowhere.

The downward stroke delivers the most propulsion. Keep your leg straight and kick down slowly, bending the knee slightly on the upward stroke. You will find long leisurely fin strokes will use little energy and give you exceptional forward movement.

It is also important you have a good horizontal profile in the water because if you are swimming almost upright across the bottom you create a huge amount of resistance. Stay streamlined, keep your arms at your side and ensure all your gear is tucked and clipped close to your body.

Big fins
Ensure you have a good horizontal profile in the water (hint: this isn't good)

Entry techniques

It is common for similar dive sites to have a completely different entry styles, and shore diving is no different.

Boat diving will in most instances involve either a backward roll or a giant stride depending on the size of the boat and the bottom contours. A giant stride off a jetty onto a submerged object is no fun.

Giant stride
Preparing to do a giant stride off the boat in Aqaba, Jordan
Giant stride
Doing a giant stride - note the inflated BCD, and hand over regulator and mask to hold them in place.

A giant stride can be a long drop to the water on a large boat that does not have a dive platform and it is important to ensure the area is clear before you leap.

Giant stride
Hitting the water, still holding mask and regulator in place

Doing a backward roll off an inflatable has its hazards. Ensure everyone rolls at the same time to avoid landing on the person next to you. Even the slightest hesitation can result in the boat drifting slightly and you landing on a diver. Ensure that your BCD is inflated, and that you have your hand over your regulator with your fingers on your mask to hold them in place. If someone does land on you, don’t panic – just relax, remember to breathe, and wait to pop to the surface.

Underwater below the boat
It can get crowded around the boat, which is why it's important to roll off exactly when the skipper tells you to

Shore entries may have you walking through the surf to get some depth and even a small wave can knock you off your feet. Clambering over rocks at some dive sites will find you slipping and sliding about so watch the waves and time your entry and exits.

If you aren’t already wearing your mask, make sure it’s around your neck or with the strap pushed well up over your forearm, NOT on top of your head or inside a fin! Or preferably on your face already. Ensure you have your fins clipped correctly and slide the straps up over your forearm so that if you stumble and place your hands instinctively in front of you they shouldn’t get lost. As soon as you are waist deep don your fins and swim away from the shore.

Irrespective of the style of entry, before committing to enter the water ensure your gear is clipped, weight belt tight,  zipped up suits and gloves are on. Ensure your mask is on and secure and your regulator firmly in your mouth, This will ensure that should you be toppled over by a wave you will be able to see and breathe. Likewise when doing a giant stride or backward roll, place one hand on your weight belt, the other over your face with the palm holding your regulator in and the fingers holding your mask firmly on your face.

The perfect diver

One of the first concerns many qualified divers have is buoyancy and their air consumption. As an Instructor, skipper and Divemaster I am often reminded of my own concerns when I started diving. Don’t envy the diver on the boat staying down the longest on the smallest cylinder. Dive often, enhance your training, hone your skills and soon you will be that diver,  first in and last out, with air to spare.

It makes no difference who your Instructor was, which certification agency you obtained your qualification from or where you are diving. All divers are taught the basics of diving during their initial training. However, the duration of your qualifying dives has a huge impact on your level of competency at the end of your training.

If you have done four, or five in some instances, short twenty minute dives (the minimum for PADI) and – let’ s presume – you spent two hours in the water during your confined water training then your total bottom time will be less than four hours. However if your qualifying dives were 50 minutes each it will be the case that your total bottom time when you’re newly qualified is a lot more.

Some people take to diving instantly and do not find any aspect of the training intimidating and within two hours of getting into the water they are relaxed, have good buoyancy and controlled breathing. For others it is a little harder coming to terms with the heavy gear, good buoyancy control seems to be a distant dream and managing to get 30 minutes on a 12 litre cylinder in shallow water is out of the question.

With bottom time comes perfection. This involves becoming comfortable with your gear so you instinctively find your pressure gauge, being correctly weighted (a huge factor in air consumption), being warm, and moving slowly with the correct profile. All of this improves air consumption dramatically.

Another important factor is confidence. Diving beyond your ability and training, doing a dive you feel you should rather not be doing are huge ”gas guzzling” factors so don’t do that deep dive to a wreck because you feel you can or think you should, do it when you know you can and really want to.

The learning curve for a diver is steep and for me the most rewarding aspect of teaching diving is to watch and be a part of a students initial flapping around in the water like a fish out of the water, to becoming relaxed, calm and confident, and watching them grow into a competent diver in such a short period of time.