We took a trip to Seal Island in False Bay to see the white sharks there, in late July. I’ve already posted my video footage from the cage. We also took some photos – mostly Tony. The trip entailed getting up very early, so as to be at Seal Island by sunrise. Once there, we scanned the horizon for predatory behaviour: typically, the white sharks here attack the juvenile seals from below, often launching their entire bodies out of the water in an explosive burst of energy.
Video still of one of the great white sharks we saw
It was a very rough day with a swell of about five metres, and from speaking to people who come to Seal Islandoften, I gather that the sharks tend to be less active on days like this. Their accuracy in striking the seals is reduced by the movement of the water column. Nonetheless we did see a couple of predation events, with the characteristic flock of seabirds waiting to pick up any leftovers, and the slick of “oily seal juices” (to quote Gary!) left on the surface afterwards. The sharks are so quick that if you’re looking the wrong way, it’ll all be over by the time you turn around.
Shark Explorers doing their thing
Investigating the bait on the surface
White shark in False Bay
After some time watching natural behaviour, a decoy (surprisingly realistic looking, made to resemble a young seal) is towed behind the boat, to try and elicit breaching behaviour from the sharks. We didn’t have much luck here, again probably because of the surgy seas, but one shark made a few investigations of the decoy before losing interest.
White shark next to the boat
Finally sharks are attracted to the boat using chum, which is mostly fish oils and other fishy substances. A tuna head was splashed in the water near the boat, and when sharks came to investigate it they were visible from the cage. While in the cage we breathed off scuba regulators, which was great. Trying to breath-hold or snorkel while the sea was so choppy would have been next to impossible. The sound of the bubbles emanating from our regulators didn’t bother the sharks at all.
Bernita and some stormy seas
We spent about twenty minutes (or maybe more – I am not sure) in the cage, some of it just waiting for action, and some of it with our full attention focused on the enormous fish swimming by and looking at us with its black eyes. Five minutes of looking at a great white shark, eye to eye, gives sudden perspective on life and the natural world. I’ll recommend this experience to anyone who will listen!
Summer winds are fading and winter winds are slowly starting to arrive. The visibility of the Atlantic sites drops off and the water in False bay gets cleaner and cleaner as if pumped through a filter. A whole new range of creatures start to make an appearance while other creatures hide somewhere warmer. There are still several giant short tail stingrays hanging around at Miller’s Point, where the fishing boats drop the fish guts overboard near the slipway.
Ray at the slipway
Many people feel it’s too cold to dive in winter… It is cold for sure, but with the right gear and on the right days, winter diving in Cape Town beats anything summer can come up with. Currently False Bay is clean and the temperature is around 15-16 degrees. By adding a shorty, decent gloves and a thicker hoodie you are all set. Dry suits, or damp suits as I call them, do also work, when they work. I don’t sell gear but I am very happy to give advice on whether a deal is a deal or a rip off!
Sevengill cowshark
We had fair conditions last weekend and dived with the sevengill cowsharks (thanks to Tamsyn again for the awesome photo!) and the seals on Sunday. It was surgy and the viz wasn’t the best but Shark Alley was swarming with sharks. Unfortunately the seals didn’t want to come and play because of the swell. Fortunately the reef around Partridge Point is stunning! The wind has been north and west a few days this week and the visibility has improved.
Weekend plans
As for the weekend – tomorrow looks the best, but Saturday could work for one launch to Tivoli Pinnacles or an early double tank dive to Atlantis and Outer Castle. The wind comes up very strongly around lunchtime so we want to be out of the water early. Sunday will be wetter on the surface than it will below so I guess it’s a stay at home and watch Formula 1 instead.
As usual text me if you want to dive tomorrow or on Saturday. We are really looking forward to our Durban trip on 17 June, which is getting closer. There is still space on this trip and our Red Sea liveaboard trip in October, so give it some thought and let me know if you want more information.
One of the divers on the boat two weeks ago took this video of the seal we saw at the slipway. Keep watching right to the end!
Steps is a long, narrow reef running for about 4 kilometres in a north-south direction, making it ideal for drift dives on days when the current is strong. It’s relatively narrow, and ranges from about 13 to 16 metres’ depth. The reef is made up of a series of overhangs and gullies, providing abundant habitat for fish and other marine life.
Sea star resting against the reef
Boxy (female)
Rock cod resting in the coral
Tony filming a knifejaw on plate coral
Boxy (male)
Sea fan at Steps
I was happy to see both a male and a female boxy – I love these fish, and their nonchalant ways. We didn’t see any large creatures on this dive except for turtles, but I enjoyed the opportunity to try some fish photography. They just won’t sit still! Yellow and blue banded snapper are the only ones who oblige the cameraman, as they seem to be remarkably placid and reluctant to break their tight formations over the reef.
Emperor angelfish having a snack
Oddly, I got cold towards the end of this dive, and surfaced for that reason rather than being low on air or time. I think it was because we didn’t actually have to swim much, and I’m a lazy finner to begin with. I never believed I’d get cold in 25 degree water, but with a lowered core temperature from dives earlier in the day it can happen!
It seems like yesterday that I was proudly waving about a new pair of blue Seac Sub gloves. Something like 120 dives later, and they’re in quite bad shape… Some of the fingers have punched through, and the seams along the side of my wrist split recently. Boat diving off a rubber duck, towing a reel and camera work are quite hard on gloves, and there’s quite a high attrition rate in the Lindeque household.
Seac Sub 3.5mm gloves with velcro wrist strap
Enter the new pair of Seac Sub gloves that Andre supplied me with in the middle of November. They’re 3.5 millimetres thick and seal at the wrist with a velcro strap. The seams around the two middle fingers ensure that flexing and dextrous work is comfortable (as comfortable as it can be in thick gloves!). I’ve tested them in the Atlantic and so far so good. I am rather fond of the Seac Sub brand, and my BCD is also theirs.
The old blue pair have been glued, and now live in the “glove box” for students to borrow.
Goot, Tami, Tony, Clare, Gerard and Cecil, ready for a night dive on the Aster
I’ve never done a night dive off a boat before, and never gone deeper than about 12 metres on a night dive, and so it was with mixed feelings that I signed up for a night dive on the MV Aster in Hout Bay, on the evening of 17 September. We’d spent the morning diving in Hout Bay harbour as part of an OMSAC-organised underwater cleanup, and in the afternoon Underwater Explorers was running some boat dives. The visibility on the 2.30pm dive we did on the Aster was passable – not midsummer Atlantic clarity, but a respectable 8-10 metres. I spent most of my time on the deck in the centre of the wreck, on top of the bridge, and around the base of the mast. A strong current was pushing into Hout Bay. The wreck is at about 30 metres on the sand, and the deck is at about 24 metres. The top of the bridge is at 19-20 metres.
A tube worm retracts into its shell
We launched for the night dive just before 6.30pm. On the boat was Tony, who has done lots of night dives (many off a boat, too), me (who has done lots of night dives, but all shore entries close to the city lights), Tami (ditto), and Goot, Gerard and Cecil, who were all doing their first night dive EVER. I don’t think they realised how awesome they were… Descending 25 metres onto the deck of a wreck, into the 11 degree waters of the Atlantic, in the dark, is something quite special!
The Aster is eerily illuminated by our torches
We rolled into the water just before 7.00pm, and descended on the shot line. The first few moments were quite disorienting – it was very dark, much darker than the surface conditions hinted it would be, and it took a few moments for my eyes to adjust and for me to figure out where I was on the wreck. Soon I was more relaxed, and I managed to hunt down the tiny basket stars I’d found on the afternoon dive so that I could show them to Tami. I was glad that I’d done an afternoon dive on the same site – it helped with orientation in the dark, and I enjoyed going back to places where I’d seen things a few hours earlier to check whether they were still there.
Basket star feeding at night
Tony and I were wearing our Christmas strobes – awesome little gadgets except that the gaps between the flashes can be a bit long when trying to do a quick head count. We also had multiple cyalumes and some rather old glow in the dark Bright Weights (weights is a misnomer here – they are in fact positively buoyant). Those didn’t work too well, but we’re not going to give up on them just yet – perhaps more time under a bright light and/or in the sun will charge them better.
The mast of the Aster at night
Doing a safety stop in the dark is a challenge. I didn’t realise how much I rely on having a visual reference – even just watching the depth on my dive computer – to manage my buoyancy at the end of a dive. Using other divers as a reference is not ideal – what if they’re using ME for a reference too? This dive was the first time I’ve used the backlight on my Suunto D6 since I’ve had the computer (about 40 dives), and I realised that the default setting it’s on (illuminates for 5 seconds) is hopelessly and irritatingly too short for a safety stop in the dark. I was also wearing an unbelievably buoyant second wetsuit over my usual Mares Trilastic, which had me shooting towards the surface like a very large cork every time I broke the five metre mark. All this aside, we managed – all of us, together – a safety stop, and then we were on the surface around the buoy, looking for Richard and the Underwater Explorers boat.
The Underwater Explorers buoy on the surface
It was very, very peaceful on the surface (until Gerard started on about the crotch strap of Cecil’s new Poseidon wing, purchased for his forthcoming cave diving adventures), and the air wasn’t cold at all. Getting on the boat was a bit of an exercise – dive gear being predominantly black. The boat was far enough from shore that there was very little ambient light to assist the skipper and us in stowing our kit properly, but Richard was organised and quick, and we managed. We had a wait of a couple of minutes for Alistair and his two buddies (all on twins) to surface, and then we headed back to dry land, a warm shower, and the deep sleep that always follows a day of diving.
Tami, Gerard and Cecil waiting to board the Underwater Explorers boat
Dive date: 17 September 2011
Air temperature: 23 degrees
Water temperature: 11 degrees
Maximum depth: 25.3 metres
Visibility: 10 metres (always tough to estimate on a night dive, but we did do a dive at the same site a few hours earlier)
Roman Rock lighthouse stands near the entrance to the navy harbour in Simon’s Town. In its general (I use the term very loosely) vicinity one finds – amongst other sites – Tivoli Pinnacles, Castor Rock, Wonder Reef, Rambler Rock, and, of course, the Roman Rock reef system, which is right under and around the lighthouse. Grant didn’t drop the shot line right at the lighthouse as one would to dive Roman Rock itself, but at a set of pinnacles called Roman’s Rest which are at the eastern end of the Castor Rock reef complex. Wonder Reef is at the western end.
A flagellar sea fan swaying in the surge
Tami and I agreed that this was one of the most beautiful dive sites we’ve visited in False Bay – it’s comprised mostly of large granite boulders and huge flat, sloping rocks that are rich with invertebrate life. The whole area is populated by various types of sea fan, giving the effect of an underwater forest.
Flagellar sea fan
Sinuous sea fan, side-on
Sinuous sea fan on the reef
Close-up of the branches of a flagellar sea fan
Palmate sea fans
Palmate sea fan
Cauliflower soft coral
Flagellar sea fans, cauliflower soft coral, and a palmate sea fan
Close up of a palmate sea fan’s branches
Palmate sea fan at Roman Rock
Sinuous sea fans
Sinuous sea fan
Sunburst soft coral
Lots of cauliflower soft coral on top of the reef
I was a bit cold (it was the second dive I did that day, and I had not put on enough layers of wetsuit to compensate for the freezing boat rides to and from the sites!) so I didn’t manage any half-decent photos of fish. But we saw Roman (of course!), and a large school of hottentot or other nondescript silver fish hanging in midwater over the reef. There were many nudibranchs – contrary to our usual experience of seeing one at a time, we saw several that were often so close together that I could include them all in one photo.
Sea fans stand like small outcrops of trees over the reef
The part of Roman Rock that we dived is a newish area, I think, that Peter Southwood is busy mapping for the Diving the Cape Peninsula and False Bay wikivoyage site. It’s a very, very special site – highly recommended. With the right equipment and good visibility, lovely wide-angle photographs can be possible.
A six-legged granular sea star
There are a couple more pictures from this dive in the newsletter Tony put out in the week after we dived the site. The surface conditions were horrible but you can see that the visibility was very good indeed (by False Bay standards!).
Orange gas flame nudibranch
Blue gas flame nudibranch
Ascidians in the (shallower) red bait zone
A sponge crab on a palmate sea fan
A serpent-skinned brittlestar
Fish schooling in midwater above the reef
Red chested sea cucumbers
Silvertip nudibranch
A blue gas flame nudibranch
Strawberry sea anemones
Two silvertip nudibranchs flank a blue gas flame nudibranch
I’ve been wearing a fantastic new wetsuit for the last few months: the MaresTrilastic 8-6-5. Like Tony’s Mares Flexa 8-6-5, the Trilastic (which is just from the new range) is 8 millimetres thick on the torso, 6mm on the upper arms and thighs, and 5mm on the forearms and calves. The one I have is from the She Dives line by Mares, which makes allowances for women’s body shapes.
Wearing a loose hoodie and an anorak over my wetsuit
With it I wear a loose hoodie, and my booties and gloves go over the bottom of the wetsuit ankles and wrists, not underneath. There are two reasons for this:
The Trilastic doesn’t have zips on the legs and arms
The wrist, neck and leg seals are kind of special and seal very tightly against my skin (except for the neck seal)
The wrist and ankle seals don’t have zips and are quite delicate. Wearing the booties over the leg seals involves a bit of gymnastic stretching to get the zips closed, but it results in warm water trapped very effectively inside the wetsuit and boots. Unfortunately it makes me look extremely bulgy after a dive because the water can’t escape, but it keeps me warm!
I like the small zip at the front – it makes a big difference to my experience of seasickness, since my old ScubaPro presses very uncomfortably on that little dip at the bottom of one’s neck. This contributes greatly to the urge to hurl! There’s still fabric touching on my neck, but not nearly as firmly or tightly as a wetsuit with just a back zipper. I actually wanted a wetsuit with a front zip, but in the thickness I wanted (i.e. VERY) there wasn’t anything available for ladies.
Accidental photo of the Mares Trilastic neck detail
With it I have a 0.5 millimetre thick Mares Rash Guard. It’s very warm but I do find the stitching a bit coarse and I have to be careful how I line the seams up on my arms and torso. The wetsuit seals so tightly that after some dives, however, my arms even have dry patches on them. I slather vaseline on the skin in the front of my neck before repetitive dives, because I get an uncomfortable chafe going on there if I spend a day in my wetsuit and rash vest.
The sleeves of both the wetsuit and rash vest are a bit long (or perhaps my complaint should be that I have short arms). I suppose I can have them adjusted (might be cheaper to do the sleeves rather than the arms). In the mean time I make use of Gerard’s patented plastic bag donning technique for wetsuits.
I can still wear a shortie on top of the 8-6-5. It remains to be seen whether Atlantic diving will require this.
Let it be said that I was warm – very warm – despite Grant’s notoriously fast boat driving, wind chill and having just completed a deep dive in 12 degree water while wearing a wetsuit. The fact that I looked like a “jellybean” (thanks Tinus!) or “the Michelin man” (thanks husband!) and that EVERYONE on the boat was laughing at me is neither here nor there. Diving is not a sport for the image-conscious…
Naughty husband Tony got me a new pair of booties from Andre recently – my old ones were getting a bit long in the tooth and were exceptionally well-ventilated.
They’re the same ones Tony has been wearing for a while, and have made a huge difference to his overall warmth in the cold Cape water. They’re 5 millimetres thick with very rugged soles, perfect for shore dives and the kind of rock clambering we sometimes find ourselves doing at sites like Sunny Cove. Diving in Cape Town is hard on kit, and the water is cold – so these are perfect for the conditions here.
What’s more, I feel like Lady Gaga with my platform heeled booties as I prance around Long Beach parking area!
The idea for this experiment was born after a few dives Tony did last year, wearing his dodgy old wetsuit, in very cold water. He’d emerge from the water almost paralysed, unable to speak, shivering uncontrollably. His muscles would cramp, and he’d struggle to breathe for a time. It’d take him quite a long while afterwards to regain his comfort level.
We wondered just how much a lengthy submersion in cold water affects one’s body temperature when wearing a wetsuit (two 5 millimetre layers, plus a hoodie and gloves). I’ve been trying to remember to take a thermometer with me to dives for months, and finally – on the day of two planned dives in False Bay in early February – managed to remember to pack it into my bag.
Since Tony is now diving in a drysuit on deeper dives, the person whose temperature was to be measured was yours truly. I don’t get as cold as he does – I have more body fat, for one thing, and for another I learned to dive in the Cape and haven’t dived much anywhere else… So cold water is the norm for me. I’m also a hot sleeper, if that counts for anything – my body is quite good at warming itself!
Anyway, I took my temperature before and after both dives. My thermometer isn’t terribly reliable so I took a couple of readings each time and averaged them. Temperatures are in degrees celcius. It was a beautiful, sunny day with a warm breeze. The air temperature was about 26 degrees. Here are the results:
Five minutes after surfacing, dive time 38 minutes, depth 21.9 metres, water temperature 8 degrees celcius
34.8
For those of you (like me) who enjoy graphs, here’s one showing the same data.
Graph of body temperature before and after repeated dives
We repeated this experiment on two dives of similar duration and similar temperature in the Atlantic ocean, and the results were also a 1.5 degree drop in body temperature which had almost fully reversed itself by an hour after the dive. We’re also going to repeat this experiment on my husband, in his drysuit, to see whether the temperature changes are as extreme. I know they’re not – this time on the boat ride back to the slipway it was me whose teeth were chattering so much I couldn’t eat my Bar One, while Tony displayed a complete lack of sympathy, all snug in his drysuit pyjamas!
