Newsletter: Here today, gone tomorrow

Hi divers

Weekend dive plans

Sunday: Early morning double tank dive, location to be confirmed

Conditions last weekend were pretty good. Not much wind or swell and decent visibility. The wind and swell for the weekend ahead look great with very little of either. False Bay, on the other hand, looks a little messy from some humping south easterly wind today.

False Bay this morning
False Bay this morning

The wind dies tomorrow and stays away for the weekend. I don’t doubt that both False Bay and the Atlantic will offer decent diving if you take the time to check before you choose. I plan to launch on Sunday as early as possible for a double tank dive somewhere clean. I have family arriving at midday from abroad and want to be done by then. If you are up for a early dive let me know and I will add you to the list.

Great news

The Shark Spotters mobile app is available – search for Shark Spotters in the Apple app store or Google Play store and download it for free!

regards

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

Diving is addictive!

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Newsletter: Home stretch

Hi divers

Weekend dive plans

Saturday and Sunday: early launches (around 7 am), location to be confirmed

I am working through some student dives as we enter the final quarter of the year, so am planning launches for both Saturday and Sunday. They will likely be early double tank dives, around 7.00 am, because the wind is forecast to pick up later in the day. The location – Hout Bay or False Bay – will be confirmed tomorrow afternoon when it’s clear which of all the contradictory weather forecasts are accurate! Want to dive? Let me know.

Diary

The usual Shark Spotters sign at Glencairn
The usual Shark Spotters sign at Glencairn

Check out last week’s newsletter for links to info on the Oceans of Life photo exhibition (6 October – 25 November) and Diversnight (7 November). Also, the crowdfunded Shark Spotters mobile app will be launched on Thursday 13 October with music and comedy at the Earth Fair food market. Book tickets here.

regards

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

Diving is addictive!

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Help Shark Spotters create a free beach info smartphone app!

The signs and Shark Spotters flag at Glencairn
The signs and Shark Spotters flag at Glencairn

Shark Spotters have been keeping bathers and surfers safe, and providing groundbreaking research on Cape Town’s white sharks, for over 10 years. They are currently developing a smartphone app that will provide information on sightings of sharks and other marine life, sea conditions, and other information pertinent to the Shark Spotters program.

The app will be available free of charge, but there are some development costs that have to be raised before it can be launched.

Click here to donate – every bit helps!

Newsletter: Diving 9 to 5

Hi divers

Weekend dive plans

Saturday: Shore dives at Long Beach

Sunday: Boat dives from Simon’s Town jetty at 10.00 to the wreck of the Brunswick and 12.30, site to be determined on the day

Liam and Christo near the Brunswick
Liam and Christo near the Brunswick

The cold front seems to have passed by and the second one that was meant to arrive tomorrow seems now to be giving us a miss. We had 40 mm of rain at home on Thursday, for which we are grateful. The break in the weather means there is a good chance some diving might happen this weekend!

I am going to shore dive on Saturday at Long Beach and launch on Sunday, the first dive being to the Brunswick, meeting on the jetty in Simon’s Town at 10.00am. The second dive will be at 12.30, the location weather and viz dependent.

If you want to dive, let me know!

Support Shark Spotters

Don’t forget to donate to help the Shark Spotters complete their beach info smartphone app! Also, there’s an auction and comedy evening (with Nik Rabinowitz!) at the Two Oceans Aquarium on Wednesday 27 July, also in aid of Shark Spotters’ research. There’s more information about the event here.

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!

Newsletter: Wishing winter away

Hi divers

Weekend dive plans

Sunday: Boat dives from Simon’s Town jetty to Photographer’s Reef and Roman Rock OR shore dives at Long Beach

I know we are barely past the halfway mark of winter, but the last few warm and pleasant days have got me wishing summer was here.

Some swell and lots of south easterly wind are in the forecast for Saturday, so Sunday will be the better option for diving. We will aim for a later start to see how well False Bay fares during Saturday’s onslaught. If we decide to launch the boat it will be from the Simon’s Town Jetty at 9.30 and 12.00 and the most likely sites will be Photographer’s Reef and Roman Rock.

If the conditions aren’t boat-worthy on Sunday, we’ll shore dive at Long Beach.

An app for beach lovers

The Shark Spotters centre at Muizenberg
The Shark Spotters centre at Muizenberg

Shark Spotters, who do pioneering beach safety work and shark research in Cape Town, are crowdfunding a mobile app which will provide information on beach and surf conditions, shark and other marine animal sightings, and whether the Fish Hoek exclusion net is currently deployed. The app will be available free of charge. Watch this video for more information about the app, and give your support by donating here!

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!

The NSRI SafeTRX app

At the beginning of this year, the NSRI launched the SafeTrx smartphone app. It is available in other countries, and the NSRI brought it to South Africa. I have been using it since February. It has taken a bit of getting used to with a few missteps on my part, but it now provides great peace of mind whenever I go out to sea. The app is a journey planner for boaters, with the capability of activating emergency contacts should you not return to port on time.

The app is available for iOS and Android systems. Skippers using the app can register a vessel (or more than one vessel) with the app (mine is Seahorse). You can provide a photo of the boat, its registration number, its radio call sign, and whether it has an emergency beacon (EPIRB or similar). When you depart for a trip, you select which vessel you are travelling in, how many passengers, what type of trip you’re doing (diving, cruising, safety, etc.), and an estimated time of arrival. You can also specify the route you’re taking by including waypoints on the trip map.

Once you’ve set up your journey, you can text it to your emergency contact(s). On your return to port, you re-open the app, close your journey, and have the option to text your emergency contacts again to let them know you’re home safely. These are screen shots from Clare’s phone showing the start and end of a trip with six people (including me) on board:

Text messages generated by SafeTrx app
Text messages generated by SafeTrx app

The SafeTrx app comes with a login to the SafeTrx website, which allows you to review your journeys online. You can actually see updates in real time; Clare took this screen shot from the website when I was out at Duiker Island in Hout Bay. When I started to return to Hout Bay harbour, the boat icon could be seen moving (jerkily) towards the harbour entrance.

The website information also allows you to evaluate the directness of the sea routes you follow, which is important when supporting open water swimmers, and gives useful statistics about how far you’ve travelled on the boat and for how long.

Viewing journeys on the SafeTrx website
Viewing journeys on the SafeTrx website

The first time I used the app, I didn’t set my ETA (estimated time of arrival) correctly, and left it on the default value, which is fifteen minutes after the current time. Not long after that time had elapsed, Clare (my emergency contact when she’s not on board) received a phonecall from Maritime Rescue stating that I was overdue and had she been in contact with me? She assured them that she had and that I was a first time user of the app, hence the mistake! We were extremely impressed by the speedy response, and glad to know that the system works so efficiently. Needless to say I have not made the same mistake again.

I encourage you to visit the NSRI website for more information about the use of the app, including download links. If you see me on the jetty and want to take a look at the app set up on my phone, please feel free to ask!

Google street view goes to the Antarctic

The ice-obsessed will rejoice with me at this (not at all recent, actually) news: Google has included a number of Antarctic destinations on street view. Destinations include Half Moon Island in the South Shetlands, South Georgia Island, where Sir Ernest Shackleton is buried, Robert Falcon Scott’s hut from his ill-fated 1912 expedition, Shackleton’s hut on Ross Island, an adélie penguin rookery at Cape Royds, the South Pole telescope, the ceremonial south pole, and a couple more on the Antarctic continent.

While we’re down in the Antarctic with Google, they have also provided an interactive map of Shackleton’s Endurance mission of 1914 that gives an excellent idea of the distances covered, and includes both recent and historical photographs.

The Antarctic imagery joins Google’s prior imaging of coral reefs in Australia and a view of the inside a ship.

It’ll be quite a long while (a lot of lottery plays!) before we can afford to go to the Antarctic, and the continent might be much changed by global warming by the time we get there, but in the mean time there’s Google…

Wind speed on the go

Tony taking a measurement
Tony taking a measurement

We have had a couple of spectacularly windy weekends in a row, and have had the opportunity to immerse ourselves in the weather. We have a weather station at home, and for mobile use we have a WeatherFlow Wind Meter. These are widely used by para-gliders, sailors, windsurfers, kite surfers, and others who need to know what the wind is doing at a particular location. This miniature anemometer plugs into the headphone jack on iPhone and Android devices, and takes wind readings via an app.

The app allows you to save readings, which makes them available on the internet. If you see a facebook post with a wind reading, it’s from our Wind Meter, and Tony is probably on the boat. If the wind is very strong, he’s more likely on land! An example of a recent reading (taken when I snapped the above photo of Tony) can be viewed here.

We find this very useful to correlate wind speed and direction to sea conditions. A southerly wind, for example, is particularly uncomfortable for diving in False Bay. Using his mini anemometer, Tony has been able to establish at approximately what wind speed it becomes too unbearable! One of the effects that global warming is going to have on our local weather in Cape Town is increased windiness, so I think we’ll have plenty of opportunity to play with the Wind Meter and go FULL WEATHER NERD. Watch out…

Links to help you keep track of the fleet

The CMA CGM Alexander von Humboldt, one of the world's largest container ships
The CMA CGM Alexander von Humboldt, one of the world’s largest container ships

I’ve written before about the Marine Traffic website, which uses the Automatic Identification System (AIS) that ships above a certain size are required to make use of, in order to track their location. We use it to find out about the ships that sometimes come into False Bay for shelter. Ship Finder is a similar, somewhat more user friendly variant of the Marine Traffic map. I find it a bit easier to use, especially when looking at a vessel’s path through time. If you really want to, you can see air traffic instead (warning: it’s terrifying and you may wish to unsee it)!

There is also OpenSeaMap, which is an offshoot of the OpenStreetMap project. OpenStreetMap is a crowdsourced project to create an editable world map that is free of charge. You can visit the OpenStreetMap website to see what it’s about. OpenSeaMap uses some of the OpenStreetMap data, but also includes marine information such as the location of lighthouses and buoys, and some quite limited AIS information. The map also purports to include tidal data, seabed profiles, and water depths, but is a work in progress.

Finally, there is FleetMon, which requires an email address in order to register. There are various account types, most of which require a subscription, as well as apps for Android and iOS (not free of charge). With a free account you can access FleetMon Explorer through your web browser, and it’s a rich AIS interface with a huge (nearly 400,000) vessel database and beautiful maps. You can create a “fleet” of vessels you’re particularly interested in, and track them around the world. However (and this is quite a biggie) you only get five minutes of FleetMon usage per day. If you want more, you have to pay.

In order of usefulness and accessibility, then, I’d look at Ship FinderMarine TrafficOpenSeaMap and FleetMon. Ship spotters will find some useful tools in that list!

Article: Phenomena on blue whale earwax

Ed Yong at Phenomena writes about the information that can be gleaned from a plug of blue whale earwax. Earplugs of blue whale wax look a bit like battered candles, and contain alternating layers of dark wax (from when the whale is migrating) and light wax (from when the whale is feeding). Counting rings of earwax provides a way to estimate the age of blue whales – there are two rings for each year of the whale’s life.

The wax also absorbs pollution from the whale’s environment, and contains some of the hormones that the whale’s body produced in life. Researchers at Baylor University analysed a plug of wax from a male blue whale that died as a result of a ship strike and washed up on a beach in California. From concentrations of testosterone and cortisol (a stress hormone) they were able to determine when the whale reached sexual maturity. They also found a disturbing array of pollutants including DDT and mercury. Sadly, the highest concentration of pollutants appear in the earwax from the first six months of the whale’s life, suggesting that they were passed along in its mother’s milk.

The scientists intend their study to be a “proof of concept” – they only analysed a single earplug, but these samples exist in museums around the world and should be kept and studied from future whale necropsies. Science at work!

Read the complete article here.