Article: Wired on mapping a sunken aircraft carrier reported on efforts by NOAA to survey and map the USS Independence, a sunken aircraft carrier lying in over 800 metres of water near the Farallon Islands. She was scuttled in 1951 about 50 kilometres off the Californian coast. Wanting to test an underwater autonomous vehicle called the Echo Ranger, the scientists deployed the five ton unmanned mini-submarine from a 25 metre catamaran, and flew her 50 metres above the wreck to take sonar readings.

This kind of technology is fantastic, and will enable the US government to get a better idea of the state all the junk that has been dumped in the region of the Farallons during the 20th century. I imagine a similar survey of parts of False Bay and south of Cape Point (in the areas marked “ammunition dump” on the hydrographic charts) would reveal similarly interesting items…

Read the full article here.

Green Point lighthouse

Green Point lighthouse sign
Green Point lighthouse sign

Green Point lighthouse is South Africa’s first lighthouse, commissioned in 1824, and is currently the headquarters of the South African lighthouse service. The lighthouse is instantly recognisable, constructed from immensely thick masonry and painted with red and white diagonal bands. The walls at the base of the tower are almost two metres thick, because the building material is unworked stone bound by lime mortar.

The tower is 16 metres high, with its focal plane 20 metres above sea level. Currently the light is an 800,000 candela metal halide lamp. These facts mean that the light can be seen from 25 nautical miles away. The sound of its fog horn (of a variety called a nautophone) will also be familiar to local residents and boaters. We listened to it for ages while waiting for last year’s Freedom Swim to commence.

View of the lighthouse across Beach Road
View of the lighthouse across Beach Road

Green Point lighthouse works in conjunction with Milnerton lighthouse and the Robben Island light to guide vessels safely into Table Bay, past Robben island and avoiding confusion from the myriad city lights. Technically the lighthouse is situated in Mouille Point. There used to be a Mouille Point light (commissioned in 1842) close to where the wreck of RMS Athens lies. It was decommissioned in 1908 when a light was established on the breakwater nearby. The base of the decommissioned Mouille Point lighthouse still survives at Granger Bay, and when I find it and photograph it I will show it to you.

The rotating lens at Green Point lighthouse
The rotating lens at Green Point lighthouse

The lens, a thing of beauty, was supplied by Chance Brothers; their handiwork is also visible at the Slangkoppunt lighthouse.

The lighthouse is open to the public on weekdays between 10.00 am and 3.00 pm, for a cost of about R14. You can climb up the tower and also browse the fascinating historical displays inside the building. You could also fantasise about working for the lighthouse service, and crash back to earth with the realisation that in today’s age of unmanned lights, it’s a far less romantic job than you think it might be.

As usual, everything I know about this lighthouse that I didn’t learn by looking at it (i.e. most everything), is thanks to Gerald Hoberman’s wonderful Lighthouses of South Africa book.

Article: New York Times on the health of the ocean

Humans began adjusting ecosystems on land thousands of years before they were able to do significant damage to the ocean, but in the last five hundred years or so we have been catching up in the marine environment. If you think that five hundred years of significant human impact on the oceans sounds too long and the number should be more like 50 years, read Callum Roberts’s book Ocean of Life – in fact, do that anyway.

In this vein, Carl Zimmer wrote for the New York Times about a recent paper (paywalled on Science) about extinctions and reduction in numbers of animals in the world’s oceans. The article received a large amount of attention and was featured prominently, which is great for science and for the ocean.

When writing about conservation issues it is a challenge to maintain an air of hopefulness, in order to spur the reader on to positive action rather than smothering them in despair. Many books about the health of the world’s oceans struggle to walk this line. Authors sometimes appear unnaturally chirpy about terrible subjects, or to change their minds three quarters of the way through the book, becoming a cheerleader after seven chapters of doom and gloom. Unusually, Zimmer’s article (and, by extension the paper it stems from) are genuinely hopeful, because the paper’s authors sincerely believe there is something that can be done.

(The timeline below is from the paper; click on the image to go to the original on the Science website.)

Timeline of animal loss
Timeline of animal loss

While the paper sounds a warning that “today’s low rates of marine extinction may be the prelude to a major extinction pulse, similar to that observed on land during the industrial revolution, as the footprint of human ocean use widens” and “the terrestrial experience and current trends in ocean use suggest that habitat destruction is likely to become an increasingly dominant threat to ocean wildlife over the next 150 years”, the authors are convinced that prompt and decisive action can make a significant difference. The action would need to be primarily in the form of massive marine protected areas, strategically located, as well as a decrease in carbon emissions.

Zimmer’s full article can be read here. One of the authors of the paper he reviews is Stephen Palumbi, whose Extreme Life of the Sea is an excellent introduction to the entire ocean ecosystem, written in bite sized chunks with the flair of the Guinness Book of Records (but more academic prowess, obviously).



Article: Outside on Chris Fischer and Ocearch

I am a regular reader of Outside Online, and noted with interest an article about Chris Fischer and his Ocearch project that was published earlier this year.

Local shark afficionados (sounds pompous – sorry) may recall that Ocearch assisted most of the who’s who of South African shark science with a massive research effort in early 2012 that will hopefully bear fruit for years to come. We listened to project leader Ryan Johnson speak about it at Save Our Seas in late 2012, giving a detailed and reflective perspective from one of the project participants. On the other side of the coin, some anti-science sectors of the community made a lot of noise about issues that they had invented for themselves (you may recall, for example, the hysterical “five tons of chum” warnings in the press).

The Outside article is remarkably even handed and nuanced, giving Fischer his due without blindly drinking the kool aid of white shark sport fishing and the adrenaline-fuelled machismo that manifests itself on the deck of MV Ocearch. I recommend it (and am in good company). It is an excellent read, particularly if you aren’t up to speed on the topic. It’s one that is still highly contentious (the drama just moves around the world with MV Ocearch – the current hot spot is Australia).

Read the full article here.

Visible shipwrecks: RMS Athens at Mouille Point

RMS Athens seen from the sea
RMS Athens seen from the sea
An observant visitor to the promenade between Mouille Point and Green Point may notice something man-made sticking out of the ocean, less than 100 metres from shore. This artifact is the iron engine block of the Royal Mail Steamer Athens, which ran aground here in the great north westerly gale of 17 May 1865. Seventeen ships were wrecked during this colossal gale – reports of the events of that day (including a mention of the Athens) can be seen in this historical newspaper.

The engine block of RMS Athens is barely visible
The engine block of RMS Athens is barely visible to the left of this image
It is possible to dive the wreck; indeed, owing to its accessibility from shore, it has been extensively “salvaged” in the last 150-plus years! There is more information about diving the wreck on wikivoyage, but suffice it to say it’s a shallow dive best done when there is no swell to speak of. The wreck is very broken up and overgrown with kelp and invertebrate life, by all accounts.

There’s a great article on the history of RMS Athens on the Submerge website: click here to read it.

If you want to go and see the remains of the wreck, I’ve geotagged this instagram picture of the engine block.  My photos of the engine block as seen from the sea were taken while we were aboard the Ocean Adventurer. If you’re interested in other visible shipwrecks around Cape Town, you could visit the Kakapo, the Clan Stuart, and (by boat) the BOS 400, to start with!

Seli… gone!

Panorama of the beach at Blouberg where the Seli 1 lies
Panorama of the beach at Blouberg where the Seli 1 lies

Our obsession with shipwrecks that stick out of the water is well documented. We keep a beady eye on the BOS 400, and while the Seli 1 was visible at Blouberg, Tony and I would take a drive out to visit her every few months. We haven’t been out to see her for well over a year, so I was delighted to find myself at Blouberg recently to get an update on her condition.

Look for the orange buoy - the Seli 1 is under it
Look for the orange buoy – the Seli 1 is under it

The wreck had gone from being intact when she ran aground in 2009, to looking a bit ropy, to separating into three pieces (above the surface, at least). After rough winter in 2012, a minor oil spill issued from the wreck, as part of it toppled over. That was the last we’d seen of her, but furious activity was going on behind the scenes as efforts were made to secure her removal.

Divers from the SA Navy were tasked with detonating explosives on the wreck to break her up, which they did in March 2013. This opened a compartment in the wreck from which oil leaked, necessitating a clean up operation. Finally, the remaining wreckage was cut into smaller pieces to expedite its collapse and dispersion on the sea floor.

The Seli 1 is under the orange buoy to the right of this image (hard to see!)
The Seli 1 is under the orange buoy to the right of this image (hard to see!)

Today, the resting place of the Seli 1 is marked by an orange buoy, that is hard to spot from land – let alone in my photographs above. The site has been dived by a group of adventurous locals, and apart from a lengthy surface swim it’s a possibly promising wreck for Open Water divers to dive from shore (these are in short supply in Cape Town – the only others I can think of are the Clan Stuart and the Antipolis, and perhaps the Romelia).

Scattered shipwreck: the anchors of SS Maori

The anchors of SS Maori on Hout Bay Main Road
The anchors of SS Maori on Hout Bay Main Road

Nautical artifacts – both physical objects and place names – can be observed all over Cape Town. One, which I’ve driven past many, many times without even noticing, can be seen on Hout Bay Main Road just between the Shell Garage and Hout Bay Manor. (If you want the precise location, check out this instagram post, which I geotagged.) The anchors of SS Maori, a steamship that ran aground in 1909 in a bay now named after her, are on display under the auspices of Hout Bay Museum. The wreck of the Maori is a very popular dive site, and is eminently suitable for Open Water and beginner divers owing to the depth at which she lies, and the comforting feeling one has of being close to shore whilst sheltered in Maori Bay.

The bell of SS Maori can be seen inside the Hout Bay Museum. The wreck is over 60 years old, and as Peter Southwood points out on the dive site’s wikivoyage page,

This is a historical wreck and is now protected by legislation. Removing wreckage or artifacts is a criminal offence.

Article: Randall Munroe (xkcd) on disappearing oceans

What If?
What If?

Have you ever wondered:

What would happen if all the bodies of water on Earth magically disappeared?

The answer – involving ships plummeting kilometres down to the ocean floor – is entertaining. Randall Munroe of explores this question as part of his What If? series. He has removed all the ships from the sea. He has discussed slowly draining the world’s oceans, and in a follow-up, dumping all that water on Mars. Now he drains the oceans in an instant:

The Titanic sank in about two miles of water. After it disappeared beneath the surface, the two halves of the ship took between 5 and 15 minutes to reach the bottom. Without the ocean there, it would have reached the bottom in about 30 seconds, striking it at airliner cruising speed.

As usual, it’s the stuff that happens afterwards that is the most interesting. Hang onto your seats.

Read the full What If? here.

Article: Wired on mapping the sea floor to find a plane

It is an oft-repeated bromide that we know more about the surface of the moon than we do about the bottom of the sea. There is some truth in this – in fact, an article at states that we know more about Mars than about our own planet’s ocean floor. This deficiency in knowledge was thrown under the spotlight by the loss at sea of Malaysian Airlines flight MH370 in March 2014.

In order to search for the flight in the Indian Ocean, depth survey tracks done in the 1960s (before GPS existed) are being combined with satellite sea floor maps, which are based on measurements of the height of the ocean’s surface from space. The resolution of the satellite data is low – about 20 kilometres, so it was further combined with ship tracks and other publicly available information.

You can read more about the map here, and read the full Wired article here.

100th anniversary of the wreck of the Clan Stuart

Clan Stuart sticking out of a glossy sea
Clan Stuart sticking out of a glossy sea

Yesterday, 21 November 2014, marked 100 years since the SS Clan Stuart, a British turret steamer of 3 594 tons, ran aground in a south easterly gale off Glencairn at two o’clock in the morning. She was on her way from St Helena island with a cargo of coal, and dragged her anchor in the gale. Fittingly, the anniversary of her foundering was also marked by a strong south easterly wind!

The entire crew was rescued, but returned to the ship during efforts to refloat her. She was pumped out and pulled off the rocks by a tug from Table Bay, but permission for her to enter the dry dock at Simon’s Town was refused for fear that she sink and block the entrance to the harbour. Her captain was thus compelled to run her aground at Mackerel Bay, where she now lies, in order to prevent her from sinking.

The Clan Stuart today

She is now a well known landmark to drivers on their way along the coastal road between Simon’s Town and Glencairn, as well as being a popular shore dive site. We’ve had some great dives there, and here’s a round up of some of the material we’ve published about the wreck since starting this blog:

How to find the SS Clan Stuart by road (hint: it is not hard)

What does the Clan Stuart look like underwater?

Getting close to the engine block of the Clan Stuart

On the beach at Mackerel Bay

Marine life on the wreck of the Clan Stuart

The wreck is quite heavily encrusted and there’s usually a lot to see. We’ve seen cuttlefish, small schools of two tone fingerfin, and for some reason I always see a wide variety of worms there! There is kelp growing on and around the wreck, but not so much that it’s hard to move around. On the beach we sometimes see African oystercatchers with their striking red legs and bills, and black bodies. Cormorants and gulls often perch on top of the engine block, too, giving them a convenient platform from which to go fishing.

On our first night dive together (Tony’s first in Cape Town, and my first night dive ever) Tony took a video (grainy) of some seals that joned us on the dive – you can find it in our post about Cape fur seals.

We also spotted a onefin electric ray on a dive on the wreck, whose electric personality seemed to interfere interestingly with Tony’s video camera.

On one memorable dive on the Clan Stuart (I think it was on 1 January one year, in the height of summer), we were surrounded by an agitated school of large white steenbras, who seemed to be trying to take cover behind us and on the wreck, repeatedly changing direction and swirling around us. Tony and I concluded independently that something large and toothy was chasing them, and exited the water by practically tunneling our way to the beach, trying to appear relaxed for the sake of the students accompanying us.

A few years later a group of Russian divers accompanied by two locals – diving off the boat this time – actually came face to face with a great white shark on the Clan Stuart – here is Tony’s story, Christo’s story, Craig’s story, and a short video of the shark taken by one of the Russian visitors. Undaunted by their experience they ended the dive on the beach, where I picked them up, drove them back to the jetty to get back on the boat, and they set out for another dive!

Diving the Clan Stuart

The best time to dive the wreck, in light of the above information and the typical movements of sharks in False Bay’s waters, is in winter. The visibility is likely to be better then, though it’s rarely exceptional (I would be ecstatic with 10 metres, and expect closer to six in the winter months). In summer you can expect 2-5 metre visibility. Don’t underestimate the waves on the beach, and keep your regulator in your mouth until you’re through. Save the chit chat for when you’re back on dry land!

Find out more

A team of film makers has been working on a project about the Clan Stuart for some time. Here’s some of their work so far:

You can read more about the Clan Stuart in Hard Aground, Shipwrecks of the Western Cape, and Shipwrecks and Salvage in South Africa.