Friday photo: Shark Alley, undiveable

Shark Alley with a big swell running
Shark Alley with a big swell running

You can’t believe the difference between Shark Alley when there’s a big swell, as above, and when there’s no swell at all. A shore entry would be impossible in these conditions; a boat dive would be awful, if you didn’t get too seasick on the way there to care. We’ve noticed that the cowsharks tend to leave the area for a several weeks late in winter (usually somtime in August and September), roughly corresponding with the period of time during which swells like this pound into False Bay. Tony reckons they leave to avoid the bad weather! Current research aims to determine where they go…

If you plan specially to dive with the cowsharks when you come to Cape Town, it’s worth checking whether they’re in town. All the dive operators know when they’re not around! Shark Alley is a lovely spot regardless of whether there are sharks to look at or not, but if there are no cowsharks and conditions are better elsewhere, it’d be more enjoyable to visit a different site.

A Day on the Bay: Boiling pea soup & a plane crash

Date: 6 September 2013

Ready to dive at Shark Alley
Ready to dive at Shark Alley

Lately spectacular vehicular disasters seem to follow me around. Hoping for good conditions – there was no real reason why the visibility shouldn’t be good – we set out for a dive with Open Water and Advanced students. Unfortunately the bay was filthy – we looked for clean water at Roman Rock, and found only compass sea jellies. We went south to Shark Alley, where – in desperation – we dived. It was like being in boiling pea soup, only colder. One of my students hung onto the kelp to try and keep position in the water. We had to abort a compass swim because of the surge. It was impossible to keep a heading.

Plane crash!
Plane crash!

Meanwhile, on the boat, Kate was watching a large, camouflage-painted radio controlled aircraft circling the boat and the dive site. It crashed into the water just before we surfaced. Its owner was watching frantically from the shore. Brian leaped into the water and retrieved it, and we drove to the slipway at Miller’s Point with it balanced precariously on the pontoon.

Brian gets ready to go overboard
Brian gets ready to go overboard

It started to smoke as the batteries short circuited. I told Kate – who was holding it – that if it caught alight she should throw it overboard. There was a small fuel tank that could have caused a problem if the plane started burning! Fortunately we were able to return the plane to its owner. If you recognise the plane, please tell its owner to get in touch because he must have some amazing footage of the boat at Shark Alley on the camera that was mounted on the fuselage!

Brian passes his swim test with flying colours
Brian passes his swim test with flying colours

It turned out to be a good day for fishing (Miller’s Point was packed) but not for diving.

Guest post: Christo on encountering a great white shark

Yesterday we had Craig’s point of view… Here’s Christo van Schalkwyk’s account of the Clan Stuart dive on which he and his fellow divers encountered a white shark. Christo has been diving since March 2012, and in the time since then has logged over two hundred dives, most of them here in Cape Town.

About 30 seconds into the dive, just as I got to the bottom, a little to the north of the engine block, I saw the shark approach from the south. It swam past us towards the north. It turned and swam back down the wreck in a southerly direction, on the inshore side. For a while it was out of sight. We kept looking out for it, while motioning to the other divers to bunch together and stay low on the wreck. A few seconds later we saw it approaching from the south again. I could see both eyes as it swam straight at me. When it was about three metres away it veered off slightly to swim past us, parallel to the wreck. At this point it was only about two metres away from Craig and me. I remember choosing the spot where I was going to hit it if turned back towards us.

Fortunately it kept gliding past and as the pectoral fins came past, something seemed to disturb it. It flicked its tail once and shot away to the north. (Seeing the video taken by Vlad later, it seemed as if one of us exhaling was what disturbed the shark, but this is only speculation.) After a second or two, it was out of sight and we didn’t see it again.

We crouched down low on the wreck, looking around, and repeated the instructions to the other divers to keep close and low down. At this time we saw Sergey coming towards us from a rocky outcrop (or piece of wreckage) about 3-4 metres away from the main wreck, towards the deep side. We beckoned (with some urgency) to him to come closer. He swam quite slowly towards us, but when he got close enough, we pulled him down onto the wreck with us. As he was positioning himself, his weightbelt caught on a piece of the wreck and came off. I had to help him put it back on from underneath.

We stayed where we were (just north of the engine block of the wreck) for about another minute or so. I remember looking at my dive computer which read 2 minutes at that point. It didn’t seem a viable option to surface, even though I knew Tony would be close with the boat. I didn’t fancy the notion of hanging around on the surface, trying to get all 6 divers on the boat, all the while not knowing where the shark was. After another half a minute or so, Craig and I had a hand signal discussion on what to do next. He suggested heading south down the centre of the wreck, in the opposite direction to the shark’s last known heading. I thought we should go for the beach, to the north west. We agreed on the beach and started off in that direction, staying very low.

Just before leaving the wreck, Craig’s weight belt came loose as well. I took the reel from him and held on to his BCD with one hand and the wreck and reel with the other, while he tried to put the weight belt back on. This seemed to take forever – I remember seeing Vlad sliding in under a raised sheet of steel and hiding there (and feeling a bit jealous of his nice cover…). Eventually I gave the reel back to Craig and got him to hold on to the wreck and got in underneath him to try and see what the problem with the belt was. Once the belt was back on, we dropped down onto the sand on the shore side of the wreck.

Then we had to swim over the sand, without cover, towards the beach. It took a while to gather the group together to do this. We stayed very low, flat on the bottom. As we swam the group seemed to fan out, so we stopped once or twice to reassemble. Craig kept watch to the north, while I scanned the southern arc. Once we got into shallower water the surge took us along quite quickly and the group spread out even more, but it wasn’t possible to do anything about that any more. We got tumbled a bit in the breakers on the beach, but in the end managed to help each other to the beach unscathed with only the loss of one mask.

Total dive time: 13 minutes
Boat entry, shore exit.

Christo’s diagram of the dive site, with indications of what happened where, is below. Click on the image to enlarge it!

Christo's drawing of the scene
Christo’s drawing of the scene (click to enlarge)

Newsletter: Getting it wrong

Hi divers

We spent a really great day in on and under the water working on a film shoot today without traveling more than 100 metres from Millers Point. The water was clean, the sun was out and about and the wind not too hectic. I could use about 6 such days a week, thanks.

Seahorse at the Miller's Point jetty
Seahorse at the Miller’s Point jetty

There hasn’t been a lot of diving otherwise this week, and the weatherman has been getting it wrong quite regularly, much to my annoyance. We did dive students last weekend, and while we were navigating the boiling pea soup at Shark Alley (no cowsharks at the moment – they’re on their annual hiatus) a radio controlled plane with a wingspan of about three metres crashed into the kelp near the boat. Brian did some heroic swimming, towed the plane to the boat, and we loaded it on board and delivered it to its owner at the Miller’s Point slipway. There were some tense moments when the electronics started smoking while it was on the boat!

Brian passes his swim test with flying colours
Brian passes his swim test with flying colours

Weekend dives

Deciding on whether or not to dive on weekends has been a little difficult of late as the forecasts are so often way off the mark. It’s almost a requirement to go out and take a look every evening and early every morning. Yesterday the Atlantic – well, Hout Bay – looked appalling and False Bay looked marginal. Today it’s a different story and False Bay was clean.

Never mind, this weekend we have swell, wind, perhaps rain and maybe even sun. Tomorrow early looks good, and Saturday will be OK but really surgy, Sunday will be howling… If the forecast is right. I have students, tourists and local divers so I will dive somewhere at some point if the weather looks good enough… Totally confused? Good, so am I. If you want to try for a dive, let me know and I’ll notify you if and when we hit the water.

Esti, Brian and I ready to dive at Shark Alley
Esti, Brian and I ready to dive at Shark Alley

Courses

I am currently running Open Water, Advanced and Divemaster courses, and we are getting ready to run a Research Diver Specialty course using the wreck of the Brunswick as a case study. This is a site you can dive even in a southeaster!

Coastal Cleanup

21 September is International Coastal Cleanup day, and we will be joining OMSAC and FBUC at False Bay Yacht Club, a venue with which those of you who’ve boat dived with me will be well familiar. The event details are here; if you plan to come along, you must sign up as instructed. There may be a registration fee to participate. It’s a lot of fun – we’ve cleaned at Robben Island and Hout Bay Harbour in the past – and a very good cause to get involved in. Encourage your non-diving friends to join a local beach cleanup.

regards

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

Diving is addictive!

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Documentary: Wild Caribbean

Wild Caribbean
Wild Caribbean

In the tradition of the BBC’s Great Barrier Reef and South Pacific documentaries we watched last year and earlier this year, Wild Caribbean transports one to a series of exotic destinations and – with the outstanding production values one expects from the BBC – introduces their micro- and macro- flora and fauna, as well as the physical characteristics of the location.

Narrated in mellifluous tones by Steve Toussaint, with a wonderful musical score, Wild Caribbean transported us out of rainy Cape Town to the warm, shallow (and very deep) seas of the Caribbean, the thousands of perfect palm tree covered islands, the mangrove forests, and the magnificent coral reefs. There are four episodes, and we enjoyed the middle two – Wrecks and Reefs and Hurricane Hell – the most. In the episode about the abundant shipwrecks and reefs in this part of the ocean, we saw footage of the Kirk Pride, lying in nearly 300 metres of water on the Cayman wall.

The area is prone to hurricanes, and these events will only increase in severity and frequency as the planet warms up. The episode devoted to hurricanes is both terrifying (with some amazing footage of storm surges) and comforting – in most cases, the coral reefs, forests and animals are able to recover and thrive after these severe storms have passed.

I was also thrilled to get a glimpse, in the fourth and final episode, of the cenotes of the Yucatan peninsula in Mexico, haunt of cave divers and redolent with history and spiritual significance to the people who lived there. Aerial footage (which is used extensively) of the Great Blue Hole of Belize was also alluring.

Chance of being murdered aside, the Lesser Antilles islands of Aruba, Bonaire and Curacao struck me as very promising diving destinations – particularly Bonaire. It is an extremely arid place with very little runoff due to erosion and rainfall, so the coral reefs surrounding it and Curacao are washed by crystal clear water and bathed in abundant sunlight. For divers, there is also magnificent footage of whale shark aggregations off the island of Utila, and of massing stingrays at “stingray city” at Grand Cayman, where one can stand in waist deep water and feed stingrays by hand. Humpback whales, orca and turtles also pass through these waters, which boast an almost dizzying array of macrofauna in addition to the coral reefs and tropical fish.

This is a wonderful production and we enjoyed it immensely. There is a companion book that looks beautiful, too.

You can buy the DVD here (South Africa) otherwise here.

Newsletter: Night night

Hi divers

Last Saturday we did a night dive at Long Beach. Four of the eight divers were doing their first night dives ever: Craig, Tamsyn, Dinho and Liam. Conditions were excellent and we had a great time. Photos in this newsletter are from that dive.

Liam on the night dive
Liam on the night dive

Weekend plans

As the days grow longer and summer beckons (it’s called positive thinking) we do still need to get through August, which according to the weather sites is the stormy month. There has been little sign of winter during the week and most days have been fairly pleasant. False Bay is quite clean and blue.

That all changes starting late tomorrow as a long period 6.5 metre swell rolls into the bay. That coupled with some rain will make diving a bit surgy and unpleasant, and my feeling is that it best be left alone for this weekend. If you’re at a loose end please pop down to Glencairn Beach or the far end of Long Beach to support the OMSAC Finathon, or take part if you feel up to it! Sponsorship of the divers/swimmers/paddlers can be directed towards Shark Spotters, a cause close to our hearts!

Perlemoen at Long Beach
Perlemoen at Long Beach

DAN Day

Last Saturday we attended the DAN Day at the Simon’s Town navy base. We had a tour of their dive training facility (this is most likely where you’ll end up if you need to use a recompression chamber after a dive accident), and then a series of very informative talks.

Pyjama catsharks asleep in the pipeline
Pyjama catsharks asleep in the pipeline

DAN or Divers’ Alert Network is an international organisation that provides a form of insurance whereby they will pay for any expenses related to diving accidents that your medical aid and travel insurance don’t cover. They will also pay for you to be evacuated if necessary, and these costs can be severe. However, if you choose not to take out DAN cover, they are still the people to call if you or your buddy has a suspected case of decompression illness. They have doctors on call who will guide you as to what to do, and they will arrange a chamber and evacuation if necessary (however the costs will be for your account). You don’t have to know where your nearest chamber is and whether it’s operational, because DAN keeps that information for you.

Please visit the DAN SA website, check them out, put their number into your phone (0800 020 111 in SA or +27 (0) 82 810 6010 if dialling from outside SA), and let me know if you have any questions (I might be able to help, or I can refer you to someone at DAN who can). Clare and I have cover, and it costs us about R175 per month for both of us. You can also take out cover specifically for a dive trip, if you don’t feel you dive enough to justify year-round membership. For an interesting story about someone who really needed their DAN membership, read this.

Diving and exercise

One talk at the DAN Day that was particularly interesting was about diving and exercise. Studies have found that light exercise a few hours both before and after a dive can be beneficial in reducing gas bubble formation, which is a good thing (too many bubbles cause the bends). The speaker also reminded us that one must keep fit to divediving isn’t going to make you fit, but being fit before coming diving will keep you safe and healthy.

regards

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

Diving is addictive!

To subscribe to receive this newsletter by email, click here or use the form on this page!

SDI Online Training

Bookshelf: The Power of the Sea

The Power of the Sea: Tsunamis, Storm Surges, Rogue Waves, and Our Quest to Predict Disasters – Bruce Parker

The Power of the Sea
The Power of the Sea

The Power of the Sea by Bruce Parker is a highly readable introduction to freakishly large ocean phenomena, most notably tsunamis and rogue waves (which have particularly interested me since reading Susan Casey’s The Wave). Parker is an oceanographer who has worked at NOAA.

I was grateful that the author spent some time explaining tides – the most basic oceanographic feature, universally familiar. How can some places have two high tides every day, some places have one, and some have none at all? What about the differences in tidal range around the world? I think I’ll need it to be explained to me a few more times before I’m comfortable with it, but between him and Rachel Carson we’re off to a good start.

In the early sections of the book there is a good deal of historical background provided as Parker fills in the background of modern oceanography, and I enjoyed the accounts of how understanding of tidal phenomena has assisted generals, rebels and others in achieving their goals (or thwarted them). The success of the D-Day landings at Normandy during World War II were critically dependent on predictions of the tide on five French beaches. Tidal data did not exist for those particular locations, and some intelligent guesswork and interpolation was required to determine which days would be suitable for an invasion.

Parker also discusses the expensive and difficult task of defending our coastlines – particularly urbanised, developed locations – from storm surges such as the one caused by Hurricane Katrina. The Dutch are particularly forward-thinking in this regard.

The latter half of the book is mainly devoted to tsunamis, their causes and effects, and the problem of giving advance warning of their approach. In order to understand how tsunamis and storm surges function, it’s necessary to have a basic grasp of how energy is imparted to the ocean. Most of the time the energy is from the wind, and a combination of factors may give rise to waves of unbelievable dimensions, or just to common and garden wind waves and swell. In the case of a tsunami, it is usually an undersea earthquake that gives rise to the wave. A significant portion of the book is devoted to the timeline of the 2004 Thailand/Banda Aceh Tsunami that killed nearly 300,000 people, and the afterword deals with the Japanese tsunami of March 2011 that has led to one of the largest nuclear disasters of all time at Fukushima.

Predicting tsunamis is difficult; in order to do the best job possible, one would need to be able to predict earthquakes, which is in itself very, very difficult. Not every undersea earthquake causes a tsunami. The next best approach – if we can’t predict earthquakes – is to have high-powered mathematical models that can, based on when a tremor occurs, give an indication of whether the resulting waves will be tsunami waves, or not. For this kind of predictive power a huge network of ocean observation buoys and sensors is required. Tsunami warnings are generated and quickly sent to nations whose coastlines are at risk. The notice period is potentially very short, so countries at risk from tsunamis need to have evacuation procedures and good public awareness for these systems to work properly.

All the phenomena Parker describes (except perhaps for tsunamis) will be exacerbated by climate change, which leads to more regular, fiercer storms, higher winds, and rising sea levels. This makes it all the more important to be able to predict what conditions will give rise to the conditions that are conducive to storm surges, large waves, and phenomena such as El Niño. Worldwide initiatives such as the Global Ocean Observing System (GOOS for short), which encompasses a wide range of observational projects, will make it easier to pick up tsunami waves before they reach land, and to provide real time data on developing weather and wave patterns across the globe.

You can buy The Power of the Sea here (if you’re in South Africa), otherwise here or here. For a kindle copy go here.

Newspaper man

For the last couple of months Tony has been writing a short diving conditions forecast for the Saturday Cape Argus newspaper.

Diving conditions forecast in the Saturday Argus
Diving conditions forecast in the Saturday Argus

He has to write his piece on a Wednesday evening, which is tricky – most of the weather sites seem to do a big update on Thursday evenings around 6pm. (This, by the way, explains why our newsletter always arrives after 6pm on a Thursday!)

Junior shows what he thinks of newspapers
Junior shows what he thinks of newspapers

Newsletter: Mid-winter mark

Hi divers

I would love to have a newsletter filled with amazing diving stories to send out every week, but for the last while each and every newsletter has been a challenge to write due to the lack of diving. When asked about diving in the Cape during winter I would usually claim that winter is often better than summer as we have north westerly winds that clean the bay and deliver stunning visibility. Last winter we had a dives with 15 metre visibility almost every weekend yet this year I doubt we have seen anything better than 6 metres so far.

It does appear that this is set to change over the next few days and by next week we will have the first real winter storm on Tuesday so when that’s over we should have good conditions. We are midway through winter so its long over due.

Dolphin acrobatics
Dolphin acrobatics

This weekend

It is difficult to say for sure what the conditions will be on Saturday. The wind blew from the north last night and that will move the dirty water in the top of the bay south towards the dive sites we most often frequent. Hopefully the sites around Smitswinkel Bay will be unaffected so we will plan for two or possibly three launches on Saturday and give Sunday a miss as the wind will be too strong. I think its most likely we will do Batsata Maze, Atlantis and Outer Castle as I think the water will be cleaner on the southern end of the coastline. If you want to be on the boat on Saturday text me.

Dolphins in False Bay
Dolphins in False Bay

Last weekend

We launched on Saturday, doing one dive only as we had more wind than predicted and around 5 metre visibility. After the dive we came across a pod of dolphins, I would guess there were a few hundred at least and we followed them for a while and watched the sea birds and dolphins having lunch.

Sunday we did navigation dives at Long Beach in 4-5 metre visibility and a fair amount of surge. Not the greatest.

Photographer's Reef
Photographer’s Reef

The boat

I have removed all the seats and built a dive rack giving much more space on deck. The bow rail has also been shortened so there is now more than enough space for kitting up. I have come to grips with the GPS and sonar and found and entered a lot more waypoints. We have also joined False Bay Yacht Club in Simon’s Town which means we no longer need to do battle at Miller’s Point with some of the other rude and obnoxious boaters or the baboons, not to mention the lack of proper toilet facilities and decent cell phone reception. The real attraction for me with the club is the fantastic facilities and the option of a hot shower after a cold dive as well as a very good restaurant for a coffee and lunch at very good prices.

regards

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

Diving is addictive!

Newsletter: Stormy

Hi divers

Redfingers at Atlantis
Redfingers at Atlantis

Weather, always a difficult topic and sometimes difficult to understand. Last weekend we took the boat out on Saturday unsure of the conditions, and had quite respectable diving at Atlantis and Outer Castle with mist, a bit of rain and about 6 metre visibility. Sunday we were expecting a fair amount of wind and instead had really good conditions at Long Beach. We were out on the boat again on Monday and had heavy mist to start but it cleared and we had good diving in sunny conditions.

Octopus on the wall at Atlantis
Octopus on the wall at Atlantis

This weekend seems set to be a stay at home weekend for Open Water students as there is a 5 metre swell coming into the bay tomorrow and the direction is southerly which means Cape Point won’t diffuse it for us. It rolls straight into the bay and will most likely trash the inshore sites. The shallower sites close to shore will be very surgy and this doesn’t bode well for good diving.

Atlantis sea fans
Atlantis sea fans

For the more experienced divers the offshore sites could yield good conditions as greater depths reduce the surge and the swell does start to drop off on Saturday, but a southerly wind will make the surface conditions a little choppy. I think Saturday will be touch and go but Sunday may be good as the swell is down to 2 metres and there is little or no wind.

Basket star at Atlantis
Basket star at Atlantis

The plan is therefore two launches on Sunday, sites to be decided closer to the time based on Saturday’s conditions. Unfortunately we won’t be getting in the water on Saturday. If you want to be on the list for Sunday, text me and I’ll keep you informed.

Misty morning at Miller's Point
Misty morning at Miller's Point

Lastly, don’t forget about the Cape Town Dive Festival. The dives for the Saturday are now 70% full, with Friday not far behind. You can find out what’s available and how to book by going to the CTDF website. Íf you want to know what dives we’ll be doing, you can find that list here.

Simon, Christo, Lauren, Shaheen & Mark almost ready to roll backwards
Simon, Christo, Lauren, Shaheen & Mark almost ready to roll backwards

regards

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