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Joshua Slocum in Google Earth: Cooktown to Thursday Island

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Follow Joshua Slocum’s Sailing Alone Around the World at: http://www.hazelhurst.net/Slocum

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Slocum sails from Cooktown on 06Jun1897 and by the evening of the 7th the Spray is at anchor near the Claremont Islands. Apart from in harbour at Port Denison and Cooktown, this is the only time Slocum anchors in the Barrier Reef Channel. By the next evening he wishes it isn’t. The Spray is sailing into the night at full speed ahead and passes the light-ship at the southern end of ‘m’ reef.¹ He expects there to be a beacon light at the north point; if there is one he doesn’t see it and the Spray strikes the reef. The next swell carrier her safely over but not before Slocum sees the ugly sharp coral rocks and realises just how lucky he is.

Keeping further out to sea now, heeding the advice to keep clear of the residents of Cape Grenville,  Slocum passes outside all of the islands including Home Island off the tip of the cape itself. He squares away westward in the direction of Sunday Island and shortens sail as he passes it; he doesn’t want to reach Bird Island before daylight — that island group is low-lying and surrounded by navigational hazards. On the morning of the 9th Bird Island is only 2.5 miles ahead, so he was lucky again that the current carrying him along was not stronger.

He spends the rest of the day sailing from Bird Island to Cape York, navigating Albany Pass, between mainland Australia and York Island, “as the sun drew low in the west over the hills of Australia.”

He anchors in a cove near the Tawara, an American built and skippered pear-fisher. Next day, he spends a pleasant few hours with the crew of Tawara and with the Jardine family from nearby Somerset. It turns out that Mrs. Jardine is cousin to Faamu-Sami, princess of Samoa and daughter of King Malietoa, who had visited the Spray at Apia.

From this cove, Slocum makes the short trip into the Torres Strait across to Thursday Island. He finds that celebrations are planned for Queen Victoria’s diamond jubilee on 22Jun1897, and doesn’t need much persuading to extend his visit here.


The section of Joshua Slocum’s journey reported here continues Chapter XV of Sailing Alone Around the World, and this post is a trailer for the adventure that I am retelling in Google Earth at:  http://www.hazelhurst.net/Slocum

Notes

1. On the evening of 08Jun1897, the Spray struck a reef and luckily there was enough water for the next swell to carry her over it. Slocum identifies this as ‘M Reef’; however, a search of the web delivers no information about the location of this hazard. I didn’t want to use a random reef in the animation so I had to dig further until I found an online version of a chart compiled from mid-19th century surveys by the Great Britain Hydrographic Department. The chart is made available by the National Library of Australia.

British Hydrographic Department chart showing the reefs of the Barrier Reef Channel

By close examination of the chart, I was able to find the identification letters of the significant reefs that skirt the Barrier Reef Channel. I couldn’t find all of them but at least it was clear which is ‘m’ reef.

To help anybody else who is looking for reefs in the Barrier Reef Channel using their identification letter, I have plotted them in Google Earth and kept their labels visible throughout the animation.

2. This chapter of Slocum’s book is one in which a lot of ground is covered with relatively few words. I like the animation of the model Spray to coincide with the narrative so, at times, it is necessary to move the model to a new location without accompanying voice-over. This can seem like an awkward silence and to overcome it I use two techniques:

  • The background sound effect of water lapping against the hull; if nothing else this helps to distract sufferers of tinnitus from their condition, and it does seem to work.
  • Using the ‘Show’ directive of TourMaker, I pop up labels that identify significant landmarks like capes, islands, and bays.

3. I am using an unabridged version of Sailing Alone Around the World. There are a few places where I have chosen not to speak the words that Slocum wrote as they are offensive to the modern ear. This chapter includes one such passage in which he describes the appearance of the men and women who travelled over to Thursday Island for the jubilee celebrations.

Copyright © Colin Hazlehurst, 2012

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Joshua Slocum in Google Earth: Whitsunday Passage to Cooktown

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Follow Joshua Slocum’s Sailing Alone Around the World at: http://www.hazelhurst.net/Slocum

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Captain Cook, taking Endeavour through Whitsunday Passage (named by him because 03Jun1770 was Whit Sunday), sailed through the night and arrived the following morning at: “a lofty promontory that I named Cape Gloucester”.

Joshua Slocum, a few days short of 127 years later, passes here on 26May1897. His charts show more accurately than Cook’s survey that the promontory is actually detached from the mainland and is now called Gloucester Island. The Spray hauls into the bay to the west of the island and anchors at Port Denison, close to the small town of Bowen.

Bowen at that time has a population of around 1,000; large enough to support a keen audience for Slocum’s story.

By 31May1897, the Spray, has carried Slocum safely through 350 miles of the Great Barrier Reef. Without anchoring anywhere, Slocum sails past many of the other capes, bays, and islands named by Cook:

  • Cape Upstart
  • Cape Cleveland
  • Cleveland Bay
  • Cape Richards
  • Rockingham Bay
  • Cape Grafton
  • Fitzroy Island
  • Cape Tribulation (“for here all my troubles began”)

Cook also named the Endeavour River, for it was here that H.M.Bark Endeavour was beached for repairs after she had struck a reef just north of Cape Tribulation (the reef was named unsurprisingly Endeavour Reef).

Cooktown was certainly in existence before the gold rush of the 1870s, when the settlement grew rapidly as a supply port, because Slocum reports visiting on the steamship Soushay in 1866; he didn’t see much of it at that time because he was ill with a fever.

The “lecture tour” continues when a meeting is arranged in the Presbyterian church and Slocum delivers his “story of the sea.”


The section of Joshua Slocum’s journey reported here opens Chapter XV of Sailing Alone Around the World, and this post is a trailer for the adventure that I am retelling in Google Earth at:  http://www.hazelhurst.net/Slocum

Copyright © Colin Hazlehurst, 2012

Joshua Slocum in Google Earth: South Solitary Island to Whitsunday Passage

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Follow Joshua Slocum’s Sailing Alone Around the World at: http://www.hazelhurst.net/Slocum

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After exchanging signals at South Solitary Island, Slocum continues north and on 19May1897 sails past Point Danger, named by Captain Cook after his encounter with shoals and strong currents there.

On the 20th, the Spray rounds Sandy Cape, a significant point that marks the beginning of the Great Barrier Reef. The light on Sandy Cape is visible for 27 miles and his next way point is the Lady Elliot Island light. This is important to find because Slocum is heading into a dangerous region shoals and reefs and all the charts in the world are of little use if you don’t know where you are. Lady Elliot Island is about 45 miles from Sandy Cape but it seems to take an endless time to cover that distance. Slocum concludes he is pushing against a strong current.

The Spray had sailed for hours in suspense, evidently stemming a current. Almost mad with doubt, I grasped the helm to throw her head off shore, when blazing out of the sea was the light ahead. “Excalibur” cried “all hands,” and rejoiced, and sailed on.

So he finds the light on Lady Elliot Island¹ and passes into the serene, but still risky, waters inside the Great Barrier Reef and is protected from the worst of the Pacific Ocean’s waves. Progress is good and the Spray averages 4.6knots over the next four days:

On the 24th of May, the sloop, having made one hundred and ten miles a day from Danger Point, now entered Whitsunday Pass, and that night sailed through among the islands. When the sun rose next morning I looked back and regretted having gone by while it was dark, for the scenery far astern was varied and charming.


The section of Joshua Slocum’s journey reported here concludes Chapter XIV of Sailing Alone Around the World, and this post is a trailer for the adventure that I am retelling in Google Earth at:  http://www.hazelhurst.net/Slocum

Notes

1. The  technical challenge in this part of the presentation was to simulate the light from the Lady Elliot Island lighthouse. I wanted to create a beam of white light that rotates about the location of the lighthouse; furthermore, I wanted it to have the same characteristic as the current light, which is described on charts as: Fl.W. 7.5s. This code means that the light is white and flashes every 7.5 seconds.

To achieve this I needed two things:

  • A model to animate.
  • A TourMaker directive to generate the animation.

I created the beam of light by drawing a cone in Google Sketchup and colouring it white. The cone was about a mile long, oriented along the green axis, which is north when the model is exported to Google Earth, and its apex was placed about 100 feet above the origin.

In the KML file for this leg of Slocum’s journey, I added the model as a Placemark, positioning it at the latitude and longitude of the Lady Elliot Island lighthouse (at the south end of the island). I set the visibility of the Placemark initially to zero (invisible), because I wanted to ‘turn on’ the light at the instant in the narrative that Slocum sees it.

To simulate a rotating beam I would need to animate the model by changing its orientation. By placing the origin of the model at the position of the lighthouse, a change in its orientation would have the desired effect of a light sweeping round.

I measured the angle subtended by the model and found that the edges of the cone were 15° apart. To achieve a smooth rotation, I would want each new orientation of the model to be no more than 15° away from the last one. I also knew that the beam should sweep through 360° in 7.5 seconds, in other words its angular velocity should be 360/7.5 degrees per second, which  comes out at 48° per second.

I used this information to determine how many orientation changes per second would be required to generate a smooth animation at the required rotation rate. Quite simply, if each animation step rotates the model by 15° and we need to rotate the model at 48° per second, then we need 48/15 animation steps per second (3.2), so the duration of each animation step should be 1/3.2 seconds (0.312s).

All of this is easy to code, taking only a few hours of development and testing. To control this behaviour, I added a ‘Rotate’ directive to TourMaker, and its parameters identify which model to animate, the duration of the animation, the angular velocity required, and the delay until the animation should start. This last parameter allowed me to switch on the beam as the narration reads:

Almost mad with doubt, I grasped the helm to throw her head off shore, when blazing out of the sea was the light ahead

The animation starts at the word ‘blazing’; the Placemark is made visible, the light sweeps around for 30 seconds and the Placemark is then made invisible.

Copyright © Colin Hazlehurst, 2012

Joshua Slocum in Google Earth: Devonport to South Solitary Island

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Follow Joshua Slocum’s Sailing Alone Around the World at: http://www.hazelhurst.net/Slocum

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By 18Apr1897, Joshua Slocum judges that the southern summer is over and it is time to head north away from the winter which is “rolling up from the south”. He sails from Devonport in bracing winds that carry him quickly around Cape Howe at the south-east corner of mainland Australia. He exchanges signals again with the residents of Cape Bundooro and then has a fine sail with clear skies to Port Jackson, Sydney, where he anchors in Watson’s Bay, close to the entrance to Sydney Harbour. He is impressed by the number of boats of all shapes and sizes working and having fun in the harbour:

The harbor from the heads to Parramatta, up the river, was more than ever alive with boats and yachts of every class. It was, indeed, a scene of animation hardly equalled in any other part of the world.

A few days later the weather is much rougher and a steamship, struggling into harbour from the heads, while Slocum is ashore, collides with the Spray and rips away her anchor and chain. The captain of the steamship takes the Spray in tow to pull her out of further danger and she is returned later by some of his crew¹:

But what yawing about she made of it when she came with a stranger at the helm! Her old friend the pilot of the Pinta would not have been guilty of such lubberly work. But to my great delight they got her into a berth…

Slocum sails from Sydney on 09May1897 in fair weather and with strong winds from the south-west. He falls into an easy routine, reading day and night, and occasionally trimming the sails. He remembers the struggle, several months earlier, when he had to fight southwards past these headlands, to Newcastle; he compares his life now with that of the old circumnavigators. He feels that he’s having rather an easy time of it².

Ten miles short of Port Macquarie, Slocum comes upon a yacht in distress. She is manned by the three most incompetent crew he has ever encountered; their appreciation of the perilous situation they are in is scant and their ineptitude has resulted in the loss of their sounding lead and their dinghy. They refuse his offers of help; he wants to tow them to Port Macquarie but they are not interested. He reads later, in a Cooktown newspaper, that the yacht was lost off Crescent Head but the crew was saved.

Pressing on, Slocum comes up to South Solitary Island, a “dreary stone heap in the ocean just off the coast of New South Wales”, and exchanges signals with the people on it. By way of identification, he raises the Stars and Stripes and assumes that the people ashore know all about his voyage for their next message is simply: “Wishing you a pleasant voyage”, and Slocum writes: “…which at that moment I was having.”


The section of Joshua Slocum’s journey reported here continues Chapter XIV of Sailing Alone Around the World, and this post is a trailer for the adventure that I am retelling in Google Earth at:  http://www.hazelhurst.net/Slocum

Notes

  1. To get the Spray to yaw as she was sailed back to Watson’s Bay by her lubberly crew, I needed to implement an ‘AnimatedYaw’ directive in TourMaker. This function oscillates the heading of the model, by the number of degrees in the ‘angle’ parameter, to either side of the calculated bearing between the two Placemarks that define the model’s movement over the ground.
  2. Slocum had on board “a full set of admiralty sheet-charts of the coast and Barrier Reef”. It’s worth taking a look at the journal of the man who first surveyed the eastern coastline of Australia and created the first version of the charts that enabled Slocum to have a relatively carefree voyage in these waters: Captain Cook’s Journal During the First Voyage Round the World.

Copyright © Colin Hazlehurst, 2012

Captain Cook in Google Earth: new user interface

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I have now applied the same range of techniques used for presenting Joshua Slocum’s first solo circumnavigation at: http://www.hazelhurst.net/Slocum to Captain Cook’s First Voyage Round the World at: http://www.hazelhurst.net/Cook

This means that all of the features introduced recently for Sailing Alone Around the World, like autoplay, passage highlighting, window resizing, and status information, mostly implemented using jQuery, are now part of the First Voyage for Round the World re-enactment.

Now, hopefully, I can get back to developing the Slocum voyage itself…

Copyright © Colin Hazlehurst, 2012

Joshua Slocum in Google Earth: Buenos Aires to the Straits of Magellan

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Follow Joshua Slocum’s Sailing Alone Around the World at: http://www.hazelhurst.net/Slocum.

On 26Jan1896, Slocum sails from Buenos Aires and soon runs into a gale which changes the appearance of the River Plate from silver disk to brown mud. It takes 2 days to reach the mouth of the river against a head wind, then Slocum plots a course between Point Indio on the Argentine shore and English Bank on the Uruguayan side of the channel.

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He keeps about 50 miles offshore in order to avoid the tide races around the capes. The disadvantage of this approach is that the Spray is exposed to heavier seas. One particularly mountainous wave completely submerges the yawl, but Slocum hears it coming and manages to drop all sails and climb to relative safety in the rigging.

The mountain of water submerged my vessel. She shook in every timber and reeled under the weight of the sea, but rose quickly out of it, and rode grandly over the rollers that followed. It may have been a minute that from my hold in the rigging I could see no part of the Spray‘s hull.

After his life has finished flashing before his eyes, Slocum’s first thought, in paraphrase, is: “I’m going to need a bigger boat.” Even so, he is encouraged to think that the Spray will survive the tempestuous seas around Cape Horn.

The giant wave rolls on by and the following days are more serene with light winds and a smooth sea. In these conditions Slocum often sees mirages that affect the apparent size of everything: an albatross looking like a ship and fur-seals looking like great whales.

The kaleidoscope then changed, and on the following day I sailed in a world peopled by dwarfs.

Technical note: Using my TourMaker tool, it was fun to animate the submergence of the Spray. I wanted to dip the hull 3 metres below the surface; however, the scale of the model at that point of the animation is X7500. That meant setting the altitude of the model to -22500 metres below sea level to get the desired effect i.e. right down into the Earth’s crust!  I later adjusted this to -22000.

Copyright © Colin Hazlehurst, 2012

If you haven’t seen it yet, do please take a look at the presentation of Slocum’s voyage at: http://www.hazelhurst.net/Slocum. It use the Google Earth plug-in which works in most modern browsers.

You may also enjoy Cook’s first voyage round the world at: http://www.hazelhurst.net/Cook

Joshua Slocum in Google Earth: Montevideo and Buenos Aires

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Follow Joshua Slocum’s Sailing Alone Around the World at: http://www.hazelhurst.net/Slocum.

Chapter VI is now complete, covering the voyage from Rio de Janeiro via the sand-hills of Castillo Chicos to Montevideo and Buenos Aires.

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I’m trying something new in the presentation, which is enabling the 3D building layer. Whether or not I keep this in will depend on how the performance looks. My old laptop seems to manage reasonably well.

Copyright © Colin Hazlehurst, 2012

If you like the presentation of Slocum’s voyage at: http://www.hazelhurst.net/Slocum, then you may also enjoy Cook’s first voyage round the world at: http://www.hazelhurst.net/Cook

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