Newsletter: Measuring up

Hi divers

Weekend plans

Saturday: Student dives at Long Beach, starting early (casual divers welcome)

Sunday: Boat dives from Simon’s Town jetty to Atlantis at 9.30am / Maidstone Rock at 12.00

Dive report

Last weekend we chose to dive Hout Bay, partly because I expected Simon’s Town to be a little too busy given it was nearing the end of the Lipton Cup, a sailing regatta hosted by False Bay Yacht Club. The sea was flat, with light winds and sunny weather and good visibility. We did three dives but by the third one were a bit chilly! It was sad to see all the poaching boats, and the damage that’s been done to the wreck of the Maori lately.

Diving at Vulcan Rock on Sunday
Diving at Vulcan Rock on Sunday

This weekend I think False Bay will be the place to be. We had really good conditions yesterday and the wind direction has been good for False Bay viz. There is going to be some swell so I think we will shore dive at Long Beach with students on Saturday (I’ll be focusing on my students, but casual divers are most welcome to tag along). We will hit the high seas for boat diving on Sunday. We will launch from Simon’s Town jetty to dive Atlantis at 9.30am and the beautiful Maidstone Rock at 12.00. Text or email me if you feel like a dive.

Physiology at the extremes

I attended a conference today focusing on how the human body responds to extreme conditions, with a focus on cold water immersion (but also including exposure to alcohol, drugs, and hyperthermia). It was fascinating, and one of the important things I took away from it is how important it is to take seriously our dives in Cape Town’s water. Our physiological responses and capabilities change after an extended period of time in cold water, and while you may feel that you’re still mentally sharp and fully in control, the opposite may be true, and this is when accidents happen. I’m looking forward to incorporating some of the things I’ve learned into our day to day diving activities at Learn to Dive Today.

Measuring wind speed on the boat
Measuring wind speed on the boat

Dive travel

Pencil in a trip to Ponta do Ouro in late April/sometime in May next year. We’ll start planning it early next year, but we’ll aim for five days of diving with a day of travel on each side. Start saving now! We have had amazing experiences there – some of our favourite dives were done at reefs called Doodles and Texas.

Faraway friends

We are thinking of our diving friends in far off lands – Bernita and Tamsyn, sending all good thoughts your way!

regards

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

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Newsletter: Over the rainbow

Hi divers

Weekend diving

Sunday: Boat dives to Maidstone Rock at 9.30 and Spaniard Rock at 12.00

Conditions report

False Bay has really delivered over the last few weeks. I have been fortunate to launch on 4 days this week and we have been rewarded with 15-16 degree water and really good visibility. The temperature dropped a degree today but we still had great viz, not much wind and very little swell.

Last Sunday morning we took an extremely wet (not in the forecast!) trip out to Seal Island, where we saw a couple of white shark breaches and a beautiful rainbow. On the way there and back we did feel like we were part of the Deadliest Catch reality show, though!  Andre took this picture on the boat.

Boating in rain gear
Boating in rain gear

Dive planning

These conditions look set to hold for the weekend. There is no doubt that both days will be great but I am going to pick Sunday and launch 9.30 from the jetty in Simon’s Town and we will go to Maidstone Rock for the first dive and Spaniard Rock at 12.00. Text me to book.

Rainbow over the deep south
Rainbow over the deep south

DAN Day

DAN is holding another day of talks focused on diver health and safety on Saturday 2 August, at Unique Hydra (the same venue as last time). You can see more information about the event and the program here. These events are highly recommended and I encourage you to attend.

regards

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

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Newsletter: Exploring False Bay

Hi divers

Weekend plans

Sunday: False Bay photo cruise, meet at 7.15 am on Simon’s Town jetty

Sunrise in Simon's Town yacht basin
Sunrise in Simon’s Town yacht basin

Dive conditions

We have had really good conditions for a few weeks now with visibility between 10 and 20 metres depending on where in the bay you are diving.

This weekend is however more like one of those hard to call weekends we have so often in summer. There is a lot of rain in the next two days, a 5.5 metre swell and gale force winds but that is mostly gone by Sunday. The question is where will the dirty rain water run off end up, and how much surge will remain from the south westerly swell? Not to mention the day time temperature will max out at 12 degrees.

Sunrise at Roman Rock
Sunrise at Roman Rock

I think the best weekend option is to cover the tank rack with the bench on Sunday and have an early morning meeting time (7.15 am on the Simon’s Town jetty) and do another trip to Seal Island, Muizenberg, Fish Hoek and Kalk Bay… or head south to Rocky Bank Whittle Rock and Cape Point. On last weekend’s trip we saw a breaching great white shark at Seal Island, a small pod of dolphins, and the most beautiful sunrise. There are some photos on facebook from last Sunday’s trip.

Text or email me if you want to join us on Sunday to explore False Bay, and remember to dress warmly!

regards

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

Diving is addictive!

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Handy hints: Getting respect on the boat

Do your fellow divers not give you the respect you feel you deserve? Lisa has the answer to all your problems: scare them with a high fashion Doberman hoodie! Some visual intimidation will do the trick.

Lisa in her awesome Doberman hoodie
Lisa in her awesome Doberman hoodie

She was trying out a new hoodie that was a gift from a friend on a dive just after Christmas. I thought she looked like a very friendly Doberman, but maybe it is a superhero hoodie like my Batman one. Whatever the case, it looks pretty awesome.

Bookshelf: Listening to Whales

Listening to Whales: What the Orcas have Taught Us – Alexandra Morton

Listening to Whales
Listening to Whales

Listening to Whales is marine biologist Alexandra Hubbard’s memoir of the thirty-odd years she spent studying wild killer whales, as well as other cetacean species. Morton was born in the United States, the daughter of a famous artist, but discovered her passion for cetaceans while working for eccentric dolphin researcher John C. Lilly. Her orca research took her into Canada’s remote Broughton Archipelago, where she and her husband (who passed away during the research in a solo rebreather diving accident) lived a romantic, itinerant, lonely, and very challenging life following pods of wild orca around and studying their communication.

Morton also spent time in oceanariums and theme parks, observing and working with captive orcas and dolphins. Her insights into the trauma that these unnatural environments inflict on the animals held there are illuminating, and dovetail with the observations made in articles such as The Killer in the Pool and Blood in the Waterand Death at Seaworld.

When the orcas disappeared from British Colombia’s remote waters, Morton wanted to find out why. She soon discovered the reason for their absence: there was a growing number of salmon farms, which started proliferating in earnest in the late 1980s, in the archipelago. The salmon farms used Acoustic Harassment Devices (AHDs) to chase away seals that preyed on the captive salmon. Since sound is of vital importance to orcas for hunting, echo location, and communication, the whales found the noisy environment unliveable and intolerable, and left the area. Morton’s persistence (she wrote over 10,000 letters) led to the withdrawal of the AHDs starting in the early 2000s.

The salmon farms have affected the area in ways other than noise pollution. They generate massive amounts of physical pollutants (from excess food pellets, waste products, and antibiotics used to treat the farmed fish), reducing the water quality. The salmon are also prone to infestation by parasites. Because the farmed fish are kept in such close quarters, there is unchecked spread of diseases and this can spill over to wild populations. There are also potentially serious consequences if farmed salmon escape and breed with wild salmon populations. The fish farming industry is growing rapidly in both size and vogue, and there is massive financial incentive for companies (and government bodies) to cover up the shortcomings and failures of mariculture. Morton’s work uncovering the abuses occurring in Canadian (and other) salmon farming continues to this day. She is a hero.

I think that if I’d had more access to women who were working as scientists when I was a child, my career might have panned out a little differently from the way it has. This is why I am very enthusiastic to discover memoirs by women who are respected in their chosen field, particularly when pursuing that particular field of study would seem to preclude some of the things that some people want, such as a stable family life. Whale scientist Elin Kelsey’s book Watching Giants also falls into this category. Morton’s life story is one of a wandering, resourceful, curious person who has managed to combine significant scientific output with a fulfilling life that has included raising two children, one of whom now works at NASA. Part of her son’s childhood was spent curled up in the bow of the Zodiac his parents were using to track pods of orca!

I’d strongly recommend this book to girls considering a career in the natural sciences, and to anyone else who is interested in the ocean, killer whales, fish farming, or just in interesting lives well lived. You can get a copy here or here.

Sea Dog surfski time trial (11 October 2013)

Paddlers in front of the catwalk
Paddlers in front of the catwalk

Sea Dog is a surfski time trial at Fish Hoek beach that takes place every Friday evening, starting at six in the evening. It runs for the last ten weeks of the year, and the first ten weeks (so twenty weeks, during the summer months). There is a gap in between for Christmas and New Year. It has been running for a few years, and a meet is never cancelled for any reason. We can attest to this, having gone down to the beach during a black south easter with bucketing rain, only to see a hardy group of paddlers battling it out behind the breakers in almost zero visibility.

The event is organised by the Mockes of the paddling shop in Fish Hoek, and there’s usually a photographer (apart from me) to document the event. There are usually a couple of marker buoys out in the bay, and the paddlers do a number of laps around them. I’m not sure of the details of the race format, but it starts and ends on the beach. There are participants of all skill levels, from world champions to weekend warriors.

If you’re around, it’s a lovely thing to watch (or participate in, if you’re a paddler) on a Friday evening after work. We sometimes get dinner and take it down to the beach to watch the proceedings.

Christmas gift guide 2013

Ok so this is a bit late, and if you haven’t done your Christmas, Hannukah and Festivus shopping yet, shame on you. Or just shame. Most of these ideas don’t entail going to a mall and having your personal space invaded by ten thousand hormonal adolescents. You can order online, or make a phone call or two. Get going!

Christmas at Sandy Cove
Christmas at Sandy Cove

Books

For the reader, you could check out our book reviews, arranged by topic:

I’m not going to suggest a magazine subscription – I’ve let most of ours lapse as we seem to have entered a long dark teatime of the soul when it comes to South African diving magazines. If the quality picks up, they’ll be back on the gift list at the end of 2014.

Dive gear

Check out What’s in My Dive Bag for some ideas… You can contact Andre for most of these:

Make sure you know the returns/exchanges policy of wherever you make your purchases. Some places can be difficult, and if the mask doesn’t fit it’s no good at all!

For lady divers

For the diving lady in your life (or your man friend with too much hair), what about some rich hair conditioner to apply before going in the water? Suggestions here. A pack of cheap, soft fabric elasticated hairbands is a good stocking filler.

Some high SPF, waterproof sunscreen, or a nice hooded towel for grown ups (available in one or two of the surf shops in Muizenberg) would also not go amiss.

Experiences

Don’t forget to add a memory card for the lucky recipient’s camera if you plan to gift any of these! Contact Tony for prices.

For the non diver, you could inspire a love for our oceans with one of these:

For those who need (or like) to relax

Memberships

Wall art

Clip Clop designs and prints beautiful tide charts for Cape Town and Durban and moon phase charts for the year. You can order online or usually find them at Exclusive Books.

My underwater alphabet is available for R200 in A1 size, fully laminated. Shout if you want a copy.

If you take your own photos, you could print and frame a couple, or experiment with stretched canvas prints if that’s your thing. A digital photo frame pre-loaded with underwater images is also a lovely gift for a diving friend.

Donations

For the person who has everything, or because you’re feeling grateful:

Science for the rest of us

Are you a scientist? Probably not. Nor am I. Are you interested in science and what it can reveal about the creatures, processes and threats to our oceans? Fortunately for you I have some resources to assist in your quest to stay well informed and to avoid quackery, lunacy, and the sort of utter disregard for facts that is commonly found (for example) in so-called “interest groups” on facebook.

xkcd Science shirt
xkcd Science shirt

(Curious about the shirt? Here’s the explanation.)

The scientific method

The scientific method is a process (often represented as a flowchart) followed when making scientific inquiries. There are occasional debates as to whether it’s still relevant in the age of “big data” or whether its formulation was flawed (and idealistic) to begin with. Its representation as a flowchart is frequently criticised because it makes the process seem simple and linear, with no doubling back and repetition, but these are minor quibbles, and most people who are living successfully (in the sense of being well-adjusted, mentally balanced, and rational) in the modern world can accept a certain degree of nonlinearity, the odd grey area, and a degree of ambiguity.

There is, however, no escaping the fact that the scientific method explains, at its core, how science works: have an idea, test its validity, revise and re-test if necessary, and draw conclusions. Most scientific papers are written with a flow of logic that conforms to the scientific method, whereas in practice things weren’t so neat and step by step. Presenting one’s findings clearly isn’t a bad thing – au contraire – but it can mislead non-scientists, who don’t spend their days doing experiments or gathering data to test their hypotheses, as to exactly what doing science is like.

Fortunately the University of California at Berkeley has an excellent tutorial, with diagrams, explaining how science actually works. One of the things that is key is that it doesn’t happen in a vacuum: the scientific community plays a vital role in ratifying new findings. It’s extremely unlikely that an incredible scientific advance that hasn’t been peer reviewed and accepted by other scientists working in that field is actually that incredible. The author may well be a quack.

Read the UC Berkeley article here. It’s helpful. If you want to read something by a real scientist, giving an example of how it all works, you can do a lot worse than this beautiful essay on studying belly button microbes. Not kidding.

How to read and understand a scientific paper

Paywalls are becoming less popular, and this is good for science. PLOS ONE is a good example of an online journal with free access for everyone with an internet connection. I wrote about one of the papers recently published there, here. So – anyone can get their hands on peer-reviewed (this is very important) scientific research. But many scientific papers are intimidatingly complex, and seem too difficult for a layperson to understand.

I’m willing to concede that yes, there are some papers you and I will never be able to grasp even the gist of without a lot of extra education… But with a bit of work it’s possible to get a pretty good idea of what’s potting in some of the more accessible fields of scientific inquiry. Jennifer Raff, a scientist who studies anthropology and genetics, wrote an article about how to properly read and understand a scientific paper. It’s aimed at those working in a scientific field who would need to read relevant papers to keep up to date with research.

Her article contains good advice, however, for an interested non-scientist with a bit of understanding who wishes to have a crack at reading some proper research. Some moderately hard work is involved, but your persistence will be rewarded. Unless you pick a paper about string theory, particle physics, or New Testament Greek (assuming you don’t already have a background in any of those), in which case you’re on your own.

Read that article here.

10 questions to distinguish real from fake science

You won’t only read scientific papers to learn about new findings in the fields you’re interested in. In fact, you’ll probably get most of your knowledge from blogs, news articles, and other secondary (or tertiary…) sources. How do you figure out whether you’re reading about something truly amazing, or truly bogus, without having a peer reviewed mainstream journal article at your fingertips?

Fear not. This list is written primarily with the pharmaceutical and related industries in mind, but it’s an excellent read for anyone interested in science, but not completely confident of their ability to discern legitimate science from pseudoscience (or worse). Remembering these questions – or even just some of them – will help you to be less easily swayed by each season’s new fad, no matter how much jargon the marketing team wraps it up in. The first two questions – “what is the source?” and “what is the agenda?” (or, as I like to ask, “where is the money?”) are, to me, the most important. Here’s the complete list of questions.

Getting your hands dirty

If you want something to practise your newfound skills of scientific discernment on, take a look at these – not actual scientific papers, but new advances in the field of shark science (if that’s a thing):

  1. The new Shark Safe Barrier: After you’ve read the official press release, check out these two posts from the Shark Alley blog for a different viewpoint.
  2. Two new wetsuit designs from Shark Attack Mitigation Systems, one claimed to “repel” sharks, and another that will allow you to be camouflaged from them while in the water.

See if you can figure out where the original idea or hypothesis came from, and how the experiment was designed (if there was one). What do you think about these two innovations?

Series: Deadliest Catch – Lobster Wars

Lobster Wars
Lobster Wars

Lobster Wars is a Discovery Channel production, produced by the same team who brought us Deadliest Catch (seasons 1, 2, 3, 4, 5, 6, 7) and its Tuna Wranglers spin-off. It tracks fishermen (and a woman) on board the American lobster boats that set out to fish Georges Bank from the beautiful New England harbours (and expensive holiday destinations) in Massachusetts and Rhode Island.

This is a slightly tamer version of Deadliest Catch. The fishermen work long, hard hours on occasion, but the labour is not as backbreaking as it is on board a crab boat. They are at sea for a week at a time, and the lobster traps are lighter and smaller than the crab pots seen on Deadliest Catch. The boats are small, and the fishery is a low volume, high value one – two or three lobsters in a trap is worth getting excited about.

Lobstering can be extremely lucrative, particularly during the winter season shown in the episodes of this series. Fierce competition on the fishing grounds and heavy fishing pressure on a valuable resource (which can sometimes be in oversupply) makes for a turbulent working environment – never mind the weather. While not quite as stormy as the Bering Sea, Georges Bank can throw up some extreme weather events of its own.

The fishing grounds on Georges Bank are “controlled” by different boat captains, who have time-tested locations that they return to year after year. We found this puzzling – that one could exert control at a distance over a piece of sea floor with relatively few conflicts. Or perhaps not so few – this article explains the phenomenon quite well. One source of conflict that recurred repeatedly in this series was between the lobster boats and trawlers, called “draggers” by the lobstermen. The trawlers shown working Georges Bank had outriggers, and if a string of lobster traps gets caught in their gear, the traps can be dragged for miles, and left in a tangled heap far from their original location.

The antics of the crewmen are mildly entertaining, but we struggled to differentiate them because of an apparently universal fondness for pulled-up hoodies among lobstermen. One female crew member is featured, working on board a boat called the Timothy Michael, and acquitting herself marvellously. A new crewman exclaims in disbelief that there’s a woman on board, commenting that he’s been on a boat where there’s been a dog on board, but never a woman. I was impressed by his liberal attitude, and am sure he’s in a supportive, mature relationship with an incredible human being who values his unique strengths and abilities.

This isn’t Deadliest Catch or Tuna Wranglers, but it is entertaining enough. The scenery, of New England and the seascapes, is lovely, and learning about a new fishery is always interesting. There are the usual lyrical waxings about how the “fishery is dying”, but the problem isn’t examined further, and no one dares to suggest that perhaps we’ve already eaten most of the fish in the sea, and if we carry on at this pace, we’ll eat it all.

You can get the DVD on Amazon.com.

Shark cage diving in False Bay (some photos)

Sunrise
Sunrise

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
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 Island often, 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.

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
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
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!