Newsletter: Transformation

Hi divers

Weekend dive plans

Saturday: Boat dives at 9.00 and 11.30 from Simons Town jetty (maximum depth 18 metres)

This week we launched on Monday, Tuesday and again today. Monday and Tuesday were pleasant as there was no swell or wind to worry about, however the visibility was pretty lousy. Mostly pea soup around Roman Rock and a little further south and 4-5 metres in Smitswinkel Bay.

One day of westerly wind, not even that strong, and False Bay transformed. On the wreck of the Princess Elizabeth this morning the visibility was 20 metres plus. It is quite astonishing how quickly things change.

I think the viz will remain for the weekend and Saturday is probably going to be the best day. There’s less wind on Sunday but a lot more swell and therefore surge to deal with. I have students to qualify so both dives will be to a maximum depth of 18 metres. Most likely to Alpha Reef and the northern part of Roman Rock.

Gathering around the shot line in Smitswinkel Bay
Gathering around the shot line in Smitswinkel Bay

Shark Spotters fundraiser

Get the details of the next Shark Spotters fundraiser, happening on Wednesday 31 May, here. Book directly with the Two Oceans Aquarium. Greg Bertish, author of The Little Optimist, will talk about his adventures, and about the early days of the Shark Spotters program. We have donated an auction item/lucky draw prize!

regards

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

Diving is addictive!

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Testing a shark repellent cable at Glencairn

Signage at Glencairn explaining the test
Signage at Glencairn explaining the test

Perhaps you have noticed some new signage and a little wooden hut at Glencairn beach, where an exciting test – of an electronic cable to repel great white sharks – is underway. The cable is a massively scaled up version of the Shark Shield technology with which many surfers and lifesavers will be familiar. The Shark Shield has been subjected to scientific testing, and is effective in certain circumstances.

The risers on the cable are clearly visible at low tide
The risers on the cable are clearly visible at low tide

The cable is a collaboration between the KwaZulu Natal Sharks Board (who would like an alternative to the gill nets and drum lines currently used to harvest sharks and other marine life off South Africa’s north coast), and the Institute for Maritime Technology (IMT) in Simon’s Town, a division of ARMSCOR. Shark Spotters and the City of Cape Town are assisting with the testing phase, which started in November and will continue until the end of March 2015. A permit has been obtained from the Department of Environmental Affairs.

The cable is 100 metres long, and is situated at the northern end of Glencairn beach. Cape Town is an ideal location to test things like this, because Shark Spotters has ten years of shark spotting data that will give a baseline measure for “normal” white shark activity without the cable. When something new (the cable) is introduced into the environment, changes in behaviour relative to the baseline data can be ascribed to its presence. Fish Hoek was originally mooted as an ideal beach to run the test, but the trek net fishermen were concerned for their fishing opportunities and so the test was moved to Glencairn.

The cable is off the end of Glencairn beach
The cable is off the end of Glencairn beach

The cable emits a low frequency electrical pulse that – it is hoped – will repel sharks. The electrical output of the cable poses no threat to swimmers or surfers, but for obvious reasons people are requested to keep clear of it for the duration of the experiment. The cable has electrodes on either side of it, supported by vertical risers that are marked by small orange buoys (so the cable runs down the middle of the rows of buoys in the pictures). At high tide the buoys are below the surface, but Tony took the boat past at low tide and photographed them sticking out of the water.

Shark Spotters will be monitoring the cable from the mountain above Glencairn, and a video feed will also be used to closely analyse the movements of any sharks that approach the cable. The risers on the cable (marked by the orange buoys in the photographs on this page) are semi-rigid, designed to minimise the risk of entanglement of any marine life. As it is the end of whale season in False Bay, there is not much risk of a whale visiting this location. Despite that, a boat and crew are on constant standby should an entanglement situation arise.

There is a full report on the testing phase, with an artist’s impression of the cable underwater, on the Sharks Board website, including a list of frequently asked questions (which should set your mind at ease). There’s also a great post at Round About South that includes pictures of the study area, and of the cable from the KZNSB document.

It’s important to note that this is an experiment, and no additional protection from white sharks is offered or guaranteed while the cable is in the water.

Oh buoy

Our cats (of which we have many, many) find our cars irresistibly appealing, and at the first opportunity will climb inside for an investigation. Tony once got out the gate and into the road with a car full of cylinders for filling, and a very wide-eyed Mini cat, who had climbed into the back of the vehicle while Tony was loading the tins.

Blue inspects the buoy
Blue inspects the buoy

Here’s Blue, still a little kitten, checking out (something next to) the buoy that the Divemaster (on our boat and shore dives) takes along with him on a reel and line, floating on the surface to mark the divers’ presence to boaters. She’s in the back of the divemobile. Everything gets a bit salty, and this seems to fascinate the cats – perhaps it’s one step away from bringing an actual fish home for them.

Newsletter: Winter wonderland

Hi divers

Weekend diving

Friday: Launch for cowsharks at 2.00pm

Saturday: Fully booked

Sunday: Boat dives if conditions permit, text or email if you want to be notified

Dive conditions report

We have been really busy with two groups of police divers from far inland. Most of their diving for work is in zero visibility and they have been experiencing some 15 metre viz dives for the second week in a row now. In between this I have also done a few shore dives at Long Beach and had 3 m viz on one day and 10 m viz the next day. There are huge patches of clean and dirty water around in the bay and on Wednesday we saw a few patches of red tide around.

Red tide near Simon's Town
Red tide near Simon’s Town

Dive plans

Winter diving is most definitely different. A huge swell rolled in today so we stayed off the water but will be back tomorrow and plan to do three launches. The third, to cowsharks still has a few spots open and we will leave the jetty in Simon’s Town at around 2.00 pm.

I am fully booked for a charter on Saturday. Conditions for Sunday are a little uncertain. The forecast says north easterly wind and that is seldom pleasant to dive in so we will make a call early Sunday as to whether or not we will launch.

Text or email me if you want to dive.

Huddle around the buoy
Huddle around the buoy

We attended a talk on Monday evening on orcas and dolphins and it is always so interesting to hear researchers and scientists talk so passionately about their subjects. There is also an exciting new research collaboration called Sea Search that is starting in False Bay towards the end of this year.

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, use the form on this page!

Exploring: The shark exclusion net at Fish Hoek beach

The net, with a hand for scale
The net, with a hand for scale

One Tuesday in early December, Tony escorted some members of the media – Murray Williams of the Cape Argus, and Bruce Hong of Cape Talk radio, on a dive along the inside of the shark exclusion net at Fish Hoek beach. It was just before the start of the school holidays, and since the net has been trialled multiple times by now and is working well, it’s a good time to raise awareness of the additional beach safety and – importantly – peace of mind that the net offers. I tagged along as photographer.

Over-under view of the exclusion net at Fish Hoek
Over-under view of the exclusion net at Fish Hoek

The net at Fish Hoek beach is a world first. It has a fine mesh that is highly visible underwater, and is designed not to catch anything – unlike the shark gill nets in KwaZulu Natal. The net is put out in the morning and retrieved at the end of the day, but only when sea conditions allow it. The south easterly wind can bring huge quantities of kelp into Fish Hoek bay which would foul the net, so when there is a strong south easter the net cannot be deployed.

If you’re a water person, please educate yourself on how the net works, and its intention, and share it with your friends. Even now, nine months after the trial started, I hear uninformed comments from people who have not bothered to do any reading about the net, and assume it’s the same kind of net as the ones in Durban. It’s not. The whole idea is that nothing – no sharks, no humans, no klipfish – gets hurt. Shark Spotters and the City of Cape Town have been very clear on this from the start. I had a bit of a rant about this late last year.

Murray dives down to check out the exclusion net
Murray dives down to check out the exclusion net

I digress. We went to the beach, got suited up, and went to check out the net. It was spring low tide, so at its southernmost end we were in about 2 metres of water. The net is high enough that when the tide comes in and the yellow floats rise with the water level, it simply unfurls further downwards, making an unbroken curtain. The lower portion of the net rests on the sand, with two parallel weighted lines to ensure that it lies flat. You can see that in the photo above Murray is gripping one of these leaded lines, and that there is a fairly large amount of net waiting on the sand for higher tides.

Murray and Monwa discuss the net
Murray and Monwa discuss the net

We stuck close to the net, and didn’t see much marine life on the sandy bottom. I spotted a large sand shark (when I say I “spotted” him, I mean that I almost landed on top of him). We were mutually surprised, and he zipped away into the bay, sliding neatly under the bottom of the net. I also saw a box jelly cruising along the net. Given my recent history with box jellies, I kept clear! The sea floor in the area where the net is deployed is level, sandy and free from rocks. There’s more life on the catwalk side, where beautiful rock pools wait to be snorkelled.

We were accompanied by Monwabisi Sikweyiya, who is the Field Manager of Shark Spotters. He is a hero and I always feel a bit star-struck when I see him (although he has no idea why – he probably just thinks there’s something wrong with me). He swims along the net regularly – someone does each time it is deployed, actually – to make sure that it’s released properly and hanging straight down.

After the dive
After the dive

Swimming inside the net is completely voluntary. When a shark is seen in Fish Hoek bay the Shark Spotter still sounds the siren and the flag is raised to clear the water. The Shark Spotters team are still waiting to see how a shark will respond to the net when it swims close enough to be aware of it. So far none of the local sharks have come close to the net, as the summer season when sharks move inshore has only just started. Tony was half hoping that we’d be swimming along inside the net, look out through the mesh – and blammo!  – see a great white shark. But we had no such luck, if that is the right word.

You can read the article that Murray Williams from the Argus wrote after the dive, here.

Dive date: 3 December 2013

Air temperature: 22 degrees

Water temperature:  17 degrees

Maximum depth: 2.3 metres

Visibility: 4 metres

Dive duration:  25 minutes

Liveaboard diving: Getting in

Just when we thought we’d tried all the possible ways to get in and out of the water from our Red Sea liveaboard, we learned a new one. We jumped in off the dive deck while the boat was on anchor or idling precariously near a cliff, or rolled backwards off Zodiacs. We used tail lines in a variety of configurations, did short surface swims, and generally felt like action heroes.

I am an enthusiastic practitioner of giant strides. It makes me sad that there are so few giant stride opportunities in Cape Town. These divers, on a liveaboard close to ours, were diving a wreck called the El Miniya. Their boat was tied up to the wreck at her stern. The divers jump into the water, and then swim along the side of their liveaboard to get to the stern line, before descending onto the wreck.

Here are some of the divers on our liveaboard doing giant strides into the warm darkness of the Red Sea for a night dive:

A tidy deck

Lines, mooring ropes, anchor ropes and any other piece of rope on a boat has an uncanny knack of getting knotted, tangled or generally in the way. There are a multitude of ideas and ways of keeping ropes tidy and in order, and every skipper has his own theory.

Bag in the nose of the boat
Bag in the nose of the boat

Seahorse is a boat used mostly with new students – for some, we provide their first ever boat ride – we often have people doing completely unheard of things with ropes including tossing them overboard without tying them off. I have tried to make sure I reduce the likelihood of a mishap so amongst other things I have marked the deck Port and Starboard, and the lines on the pontoons are colour coded: red for port and green for starboard.

If there is a line on the boat that should not be untied, the knots are covered with insulation tape and the most recent addition to the rope organisation system on board are these bags for keeping mooring lines off the deck and out of the way. Fenders are attached permanently at the stern to avoid them going overboard unclipped, and it is the same up front in the bow.

Storage bag
Storage bag

I have also recently moved the life jackets from the hatch in the bow to these two grey bags on the stern for easier access. The O2 unit will now move into the hatch in the bow, as it is a little more sensitive to salt water.

Life jackets live in bags next to the engines
Life jackets live in bags next to the engines

Great white shark at the Clan Stuart wreck – video

To close off Cape Town’s Shark Week, here’s the 11 second video footage that diver Vladislav Tomshinskiy (thank you Vlad!) took of the shark as it swam past the divers the second time. The bubbles at the end of the video belong to Craig (far left, with the buoy line) and Christo. Please enjoy this beautiful video of one of the ocean’s most brilliant predators, swimming curiously and gracefully past a group of awe-struck divers who are all amazed and grateful for having had the experience.

Local shark scientist Alison Kock of Shark Spotters says that from the video the shark looks to be a female (she said that if it was a male you’d expect to see claspers as it turned to swim away, which one can’t) and that she’s between 3 and 3.5 metres long. According to a recent study, most of the sharks seen at inshore locations by the Shark Spotters during the summer months are large females, who tend to be in False Bay year-round.

It’s not clear whether the shark was disturbed by the divers’ bubbles (as Christo speculates), and whether that was what caused it to swim away when it did. That flick of the tail says “I’m outta here!” and is something we’ve seen when observing these animals from the surface (on cage diving and research boats). The acceleration and turning abilities of white sharks is remarkable.

I’m interested by the bubbles because it’s an oft-repeated mantra by the shark cage diving operators (all over the country) that sharks are scared of scuba bubbles, and this is why you have to breath hold or snorkel in the cage. In July we did a cage diving trip in False Bay with African Shark Eco-Charters, who allow their clients to view sharks from the cage while on scuba, and they certainly don’t see fewer sharks than any other operator. Also, the sharks who swam past us in the cage were totally not bothered by our bubbles (of which there were many).

I therefore wouldn’t bet my reputation (or maybe I should, just to get rid of it…) on the “sharks don’t like bubbles” theory, but there may be far more nuance to it than we know. The shark in this video practically got a spa treatment on its tummy from Christo and Craig’s regulators… Perhaps to scare a shark away using air bubbles you need to get really close. But I don’t plan to test that theory unless I have to!

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)

Skipper’s notes on a great white shark encounter

I would never consider myself an expert on wild animals, but I have been diving for a while and no matter how long you spend underwater or on the water, every day can bring something new to look at. We had a very interesting experience on Saturday 14 September at one of our local dive sites. The Clan Stuart, an inshore wreck in 10 metres of water about 100 metres offshore, can be dived as a shore entry as well as a boat dive. Our group were all very experienced and mostly in their forties and fifties. Diving the wreck from the beach requires a challenging climb over the train tracks as well as a rock embankment plus a trip through the shore break. It is not for everyone, so we offer this site as a boat dive.

I took this photo of the Clan Stuart engine block while the divers were kitting up on the boat
I took this photo of the Clan Stuart engine block while the divers were kitting up on the boat

The conditions were good. The water temperature was 15 degrees, visibility 6-8 metres and there was a manageable 2-3 metre swell (it wouldn’t have been manageable if we’d done it as a shore entry). The divers rolled into the water and head over the stern of the wreck. From our boat you dive with a buoy and a reel or you stay at home. There is far too much boat traffic in Cape Town to dive any other way. I always stay very close to the the divers in the first few minutes to ensure I can attend to problems quickly.

Five to seven minutes into the dive the buoy turned sharply and headed for shore at quite a pace. I moved in a little closer and a white shark surfaced perhaps 10 metres in front of the boat and about 10 metres behind the divers. It then disappeared briefly and came back heading for the divers. I started to head towards the shark to get between it and the divers, but it swam straight for them and simply swam through the group.

It then turned and came towards the boat and surfaced again, and I tossed a weight at it, not really knowing if it would help. The shark went below the boat and I never saw it again. By this time the group had reached the shallows and two of the group, Christo and Craig, were busy getting the others out of the water. I then went back to the jetty, left the boat there and drove to pick them up assisted by Clare as we were not getting six divers with kit into either of our cars.

As with any such interesting experience there are always a lot of helpful and insightful questions, comments and observations.

The first question posed to me was from the Divemaster, Craig. Did they do the right thing? Most definitely. I think he and Christo made an excellent decision in a very stressful situation. In our briefings I always touch lightly on the recommended course of action if you see a shark or any other large wild animal, and between Christo and Craig, both regular divers on our boat, they followed that plan to the letter. I tell the divers to get into a small group, stay close together, and – if possible – stay on the sea floor. They must wait until the shark has moved away before attempting to swim off in a calm manner. On no account should they surface while the shark is still in the area.

Interestingly, everyone agreed that the shark’s size was between 3-4 metres, and that it was very inquisitive but not overly aggressive. The shark had a fair amount of time to display any aggression as the swim from the wreck to the beach can take several minutes and in fact took a fair while as Christo and Craig kept the group tightly together despite the inclination from one diver to wander off. I asked if anyone had noticed if it was a male or female as I know our resident scientist and shark expert would like that info, and got this response from Christo: “It swam straight at me, I could see both its eyes, and when it was less than two metres away it turned so suddenly that I felt the wash from its tail.”

This comment from Christo impressed me the most. “I have had no interest in seeing a white shark underwater but having seen one I can understand why people find them to be beautiful and graceful.”