Plan your dive and dive your plan

Three divers approached me at the dive centre one day, requesting I take them to a dive site where they could dive to 60 metres. They wanted to test some new equipment configurations. Two were certified advanced Nitrox divers, qualified deep technical divers and had made several dives to over a hundred metres… in a lake. The third diver, like myself, was qualified to dive to 40 metres.

So we draw up a plan: they will dive to 60 metres, spend 6 minutes at that depth, ascend to 50 metres and spend 5 minutes there, then ascend to 40 metres 5 minutes thereafter and so on until the reached 6 metres where they would switch to pure oxygen to reduce the deco stop time as the current at this site is strong. The third diver and myself would meet them at 40metres.

Using a software program called V Planner we calculated that including the descent time and ascent times for each stage, at a controlled rate, we would enter the water precisely 16 minutes after they started their dive and we would meet them at 40 metres. We would then all be together for the next 30 minutes, ascending with them to their 6 metre safety stop, ensure they had both switched to pure oxygen and then leave them and return to the boat.

The plan was that we would spend 6 minutes on our descent to 40 metres and all four of us would reach 40 metres together. They were made to clearly understand that should they have a problem at any depth deeper than 40 metres we would not be able to help them as we were diving 12 litre steel cylinders on a Nitrox 32% mix, limiting our depth – and what’s more we did not have the qualifications to go to 60 metres.

We discussed the plan in great detail and everyone was set. A red SMB would be hoisted if they experienced any difficulty and a yellow would be released once we met at 40 metres.

Mistakes happen

We started our descent on time, and watching my dive computer and timer I descended at the agreed rate. My buddy, however, did not. He descended way too fast. Believing that they would be in control of their dive he descended very fast and joined them, ahead of schedule at a depth of 55 metres. They were 3 minutes behind schedule as they had struggled to come to terms with the ocean current. Now we had a problem. I waited at 40 metres, but they arrived late, and this meant I would risk going into deco before we left for the 30 metre stop.

At this point my buddy ran out of air. He was closer to the deep divers as he was reading their slates, so he grabbed the first regulator he could see: the deco tank regulator, filled with pure oxygen. At depth oxygen is toxic and can kill you in a matter of minutes. I grabbed it out of his mouth, so he grabbed my regulator out of my mouth as he was now starting to panic. He was holding onto me so tight I could not reach my octo so I reached for the octo of another diver. So here we were three divers locked together at 40 metres, each with a regulator in our mouths that belonged to someone else. I managed to get him calmed and off my cylinder and onto the octo of the deep diver with the most air. Now back to normal, we started our ascent and did the required safety stops, reached the 6 metre stop for them to switch to oxygen and headed for the surface. I reached the surface with 10 bar in my tank.

Deep dive
Ascending from the almost disastrous deep dive on Atlantis in Ponta do Ouro. Note the hang tank of pure oxygen.

My buddy had been to 55 m on a Nitrox mix of 32%. The maximum safe depth for this blend is 40 metres. He had almost sucked on a cylinder of oxygen at 40 metres, this is a lethal dose at depth. Mistakes happen. Be meticulous with dive planning, rehearse your incident scenarios and make sure you dive your plan.

Wreck penetration

Once you embark on the Wreck Specialty Diver course you can choose to include wreck penetration if you wish.

Wreck penetration
Wreck penetration

There is more to this aspect than just having a big torch! Passages deigned for walking along become very tight spaces if the ship is lying on its side and a once narrow walk way will have you crawling along the bottom of it while your tank scrapes the top, dislodging rust from above and silt from below – reducing visibility to zero despite your huge light.

Wreck penetration
Take care not to swim into overhead environments without a reel, line and a light

Once in a wreck you need to move very slowly as the diver behind you will not have a good time swimming in the silt cloud you create. Your bubbles are also enough to create a cascade of flaked rust in some instances. It is extremely important to use a reel and line, tied off at the entrance. You belay the line at various points to prevent the line following a route you can’t navigate on your return. If you don’t do this, the line will find the shortest route through the wreck behind you – not necessarily person-sized! Cyalumes attached to the line are useful just as a back up torch or three is also an essential requirement.

Wreck penetration
Orient yourself using daylight when penetrating a wreck

Always ensure you have studied a drawing of the layout of the sections you plan to penetrate. The MV Aster wreck just outside Hout Bay Harbour was purposely scuttled by divers, for divers. As a result detailed drawings of the interior of the wreck exist, and it is an ideal site for training in wreck penetration.

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.

Bookshelf: Marine outposts and shipping

There’s a romance and fascination to the structures that we build to try to tame the ocean, and a sense of awe demanded by the scale and industry that modern harbours project. Learn about the development of modern shipping, about lighthouses, and more with this list of book recommendations for the shipping buff.

Lighthouses

Harbours and shipping

Sailing

  • The Complete Yachtmaster

Bookshelf: Two Oceans

Two Oceans: A Guide to the Marine Life of Southern Africa – George & Margo Branch et al

Two Oceans (original edition)
The original edition of G & M Branch's Two Oceans

Two Oceans is one of the better known guides to South African marine life, and rightly so. Tony is on his second copy – the first is so dog-eared that the covers have fallen off and the spine has split in multiple places. That’s the sign of a much-loved and well-used book!

It is extremely comprehensive and illustrated with photographs of the creatures and plants in their natural habitats, which is how you’d see them as a diver.

I’ve used the book after dives, but also as part of the volunteer training course I’m doing at the Two Oceans Aquarium, to identify sea plants and animals in rock pools and in the aquarium exhibits. It’s useful for the whole family, even if you’re not all divers, because it covers shore creatures as well as those found only at depth.

Two Oceans (updated edition)
Two Oceans (updated edition)

The book has been through several editions. The latest one (see the cover below) is greatly expanded, with more user-friendly contents pages (it’s arranged a lot like bird books, with colour-coded pages).

I use this book a lot; I would recommend it as a first or second purchase for a local diver. It covers the entire coast of southern Africa, so you may not find as much regional detail as you need, but that’s where the SURG publications step in and fill the gap! (More on those later.)

You can buy the book here if you’re in South Africa. Otherwise go here.

Ode to the logbook

I am a numbers person. I love to record things, analyse trends, draw graphs, and notice patterns in data. For this reason, I’m totally obsessive about filling in my dive logbook. Apart from making me happy to record all that information, and filling a wonderful hour or two after each dive looking up what I’ve just seen in the pile of books on sea life that Tony and I have amassed between us, it has had some other, unexpected benefits:

  • I’ve been able to track my progress as a diver with respect to air consumption. When I look back at early dives, I feel proud about how much longer I can stay down with the experience I’ve built.
  • I can track my progress as a diver with respect to buoyancy and lack thereof – when I started diving, the dive centre loaded me with 12 kilograms of weight, including cylinder weights. I sank like a lead cannonball. With Tony’s help, we’ve reduced my weight to somewhere between six and nine kilograms (depending on how many wetsuits I am wearing and how much custard has been consumed in the recent past).
  • I can look back on different gear configurations, and see what worked in order to reproduce successful ones: how much weight I wore and where (on my weight belt or as integrated weights or as cylinder weights), how many layers of neoprene were donned, how large my cylinder was, and so on.
  • Regional information is useful. When planning our annual houseboating trip this year, I was able to look back on the water temperature from when we dived in Knysna in 2009, and decide how many layers of wetsuit I would need.
  • Seasonal information on fish life (what appears when – for example, giant short-tailed sting rays visit Long Beach in summer), water temperatures and general conditions is useful and interesting. Now that I’ve been diving for over a year, I’m delighted to start noticing the different patterns of life… what time of year we see lots of juvenile fish, when there are lots of egg ribbons at Long Beach, how visibility correlates with water temperature, when the shaggy sea hares are out in force, and more.
  • We like exploring, and have on occasion dived forgotten sites or even places that aren’t recognised dive sites as such, but we’re curious to see what’s there. Recording dive information and what we saw makes it easy to tell others about these sites, and to assist when we decide whether they’re worth visiting again.
  • The bucket list aspect is also fun. Tony and I want to try and dive as many of the dive sites listed on Peter Southwood’s Wikivoyage site for the Cape Peninsula and False Bay as possible. Recording the dives in my logbook is like ticking the places off on a list!
The Number Two Cat understands the importance of keeping a logbook
The Number Two Cat understands the importance of keeping a logbook

Many people start a logbook as students on their Open Water course, and then lose interest. Don’t give it up – aside from these personal benefits, your logbook will be useful in at least two other situations involving other people:

  • If you go diving or want to rent gear somewhere other than where you learned to dive, or with new people (for example a club), you may be asked for your logbook (as well as your certification card). The club or dive centre may want to verify that you have the experience to handle the dives you have signed up for. If you’re certified with a lesser-known agency, your logbook can also help persuade the dive centre that you know what you’re doing.
  • For certain PADI courses you need a minimum number of logged dives (for example, 60 for Divemaster and 100 for Instructor). If you don’t have a record of the dives you’ve done, it complicates matters somewhat!

Wreck diving

There is just something so intriguing about diving a wreck and this need not be limited to ships alone. This tank wreck in the Red Sea is an amazing dive.

Sunken tank in Jordan
This tank was placed as an artificial reef by order of the King of Jordan, who is a diving fanatic!

Wrecks all have a story to tell. Some are there from navigational errors (like the Kakapo on Long Beach, Noordhoek), some from mechanical faults, some from war battles (like the HNMS Bato off Long Beach, Simon’s Town), many of them as a result of bad weather (like the Clan Stuart)  and some wrecks are the result of a planned scuttling to form an artificial reef (for example, the Smitswinkel Bay wrecks).

No matter how it got there, exploring a wreck is fascinating and within months of its arrival marine life forms move in and make the nooks and crannies home. Corals, sponges, sea anemones – to name a few – all appear and grow within months of the wreck’s arrival. Wrecks can sometimes become home to more species than you see on a nearby reef purely due to the wreck’s size, giving juveniles far more protection from rough weather than a reef can.

Despite the allure of the many opening and overhangs, wreck diving has its own set of hazards and without proper training it is important to stay out of any overhead environments. It is also critical to avoid becoming entangled in the myriad of cables, ropes, chains and often fishing tackle that can sometimes be draped over a wreck. When you start wreck diving you will most likely be content to swim around the outside and be awed by the size of some wrecks, once majestically sailing the seas, brightly painted and full of noise and life. Now they lie silent, rusty and overgrown, but still teeming with life.

A powerful dive light is a must if you want to peer inside holes and hatches, but be wary as your light can often disturb some huge creature who will buzz by you startled and dazed by your light, as you are blocking the exit.

Newsletter: Sodwana trip and diving this weekend

Hi everyone,

Sodwana Bay

The trip to Sodwana is on for the weekend of 8th, 9th and 10th of October. I have attached a breakdown of the costs with as much detail as possible (courtesy of Clare) [Note to blog readers: email me for this]. To secure the booking I need you to think quick and respond as soon as possible as I need to know the numbers. It is open to anyone that dives, students and friends of mine as well as any of your friends. The idea group size will be 8 -10 as this way we will fill a boat and therefore get to decide on the dive site. All the dives go to 2 Mile Reef, and almost every dive on this reef is suitable for Open Water divers. Sodwana claims to be the best dive site in southern Africa and rightly so, it is also the town where they have T-shirts labeled: a small drinking town with a diving problem…

Diving this weekend

I ran a competition with a Discover Scuba Diving experience for two and the winners will possibly venture into the water on Saturday. The Rescue course starts this weekend and in between we will have a fun dive to the Clan Stuart or cowsharks. Swell dependent. Saturday night, I will feed my addiction to night diving, meet at Long Beach at 6.00pm.

Sunday I am hoping to do a deep wreck dive for the Advanced students and will confirm this with the charter during the course of the day (the wind may factor this out). If you do wish to do boat dives I need to know by Wednesday as the boat launch schedule comes out on Thursday morning and the boats often fill very quickly.

I have ventured into the blog world, see link below, the idea being to post diving related info and create a forum for questions, so feel free to read, post, comment, correct me and ask away, if I do not have the answer I will find it for you and add my theories and opinions… risky I know…

Tony Lindeque
076 817 1099
www.learntodivetoday.co.za
www.learntodivetoday.co.za/blog

iMod competition winner

Following up from our earlier post, the winner of the Discover Scuba Diving experience for two has been announced on iMod.

Tony is looking forward to taking Sediqa and a friend to experience life beneath the waves… Sediqa is quite excited… Can you tell? Can you? Awesome! We will be sure to post a follow-up.

Many thanks to Chris for running the competition!