Across the Indian Ocean


After mounting disagreement with Parliament, Charles I raised his standard at Nottingham castle, beginning the English Civil war. In a few years’ time the Black Death would kill half of London’s population of 460,000. The following year a huge fire swept the city of the Plague, but 80,000 of the surviving population lost their homes to the flames.

In the America’s, the Dutch were forced to abandon their garrison on Staten Island (New York) for the safety of Fort Amsterdam after fierce attacks from the natives.

Isaac Newton was born, Galileo died and William Shakespeare had been dead for 26 years. Rembrandt was at the peak of his career.

The world had not yet seen a thermometer, screwdriver or piano.

 On August the 14th 1642, two ships, the Heemskerck and the Zeehaen, well manned, well equipped and well provisioned, slipped their moorings in Batavia. The ships were setting off in search of the ‘Great South Land’ believed to exist somewhere in the Southern oceans. Abel Janszoon Tasman had command of this voyage of discovery for the VOC (Dutch East India Company).

Abel Tasman banner

‘Batavia’ was the name of the VOC’s trading fortress in Java, Indonesia. Today, we know it as Jakarta. They were sailing out into the un-charted and the unknown, and they were already far, far away from home. The ships and crews were Dutch, and their home port was Amsterdam, half the world away.

On the evening of August 13th, Abel Tasman visited Antony van Diemen, Govenor of Batavia, and received his final written instructions. These instructions included the line;

‘You shall then, in the morning, early, after completion of mustering. go under sail together, and endeavour to come out of Selat Sunda as quickly as possible, setting course in order to get soon into the southeast trade wind, with which you shall take your way westward to the island of Mauritius’.

The start of Tasman's journal

The first page of Abel Tasman’s journal

Tasman duly set sail first thing in the morning, heading to Mauritius. At the end of that Day, Abel Tasman sat down in his cabin on the Heemskerck, and wrote the first entry in his journal.

‘This day August 14, A.D. 1642, we set sail from the roads of Batavia with two ships, the Yacht Heemskerk and the Flute Zeehaan, the wind being north-east with good weather. On the same day in the evening the Zeehaan ran aground near the island of Rotterdam, but got afloat again in the night without any notable damage, after which we continued our voyage to the Straits of Sunda.’

Abel Tasman and his two ships had barely got under way before they had a near disaster. The Zeehaen, fully laden with supplies for 110 men, ran aground before leaving the harbour. We don’t know the precise details of the incident, but it’s very likely that the crews were, to put it plainly, ‘under the weather’, and not performing at their best. By the evening he was still in the harbour, and even the next day he was only 10km from the wharf when he lowered the anchors again at ‘Anjer’ Island ( now known as Pulau Anyer ).

Ocean voyaging was a dangerous business, and many did not survive it. For the common sailors, the days preceding voyages were usually spent in the port’s brothels and grog houses. On departure one of the skipper’s first tasks was to gain a sober crew. It was common practice to leave port, and then immediately anchor up again until the effects of the gin wore off. Back at anchor Tasman set about making the two ships, and their crews, fit to venture out into the Indian Ocean.

August 15th.

‘Towards evening we went to Mr. Sweers, who was on board the Yacht Bredam, from whom we understand that at Bantam point there lay at anchor a quelpaert, newly arrived from the Netherlands; at night we anchored off Anjer in 22 fathom, where we refitted our ship which was disabled to such a degree that we could not possibly have put to sea in her.

That evening he visited Salomon Sweers, newly returned from Head Office in Amsterdam. Sweers was a big wheel in the VOC machine. At the time, the VOC was the most successful business on the planet, and Batavia was the Far East hub of that profit. The Batavia operation was run by the ‘Council of the Indies’. Salomon Sweers was both the VOC’s chief accountant in Batavia, and a member of the ‘Council of the Indies’. Sweers not only wielded a lot of clout, but he was no doubt carrying final messages from Head Office regarding Tasman’s expedition. On his return, Tasman would have to account to Sweers for all expense incurred.

Sweers returned to Holland in 1646. In his time in Batavia he accumulated a large collection of papers and artifacts, and these eventually found their way to the Netherlands State Archives. Among these documents was a copy of Abel Tasman’s Journal… the journal that is quoted here.

Tasman remained at anchor, getting everything ‘ship shape’ (crew included), before finally getting underway on the evening of the 16th. He sailed through the Strait of Sunda, out into the India Ocean, and west toward Krakatoa. 241 years later, Krakatoa would cease to be a notable landmark.

August 16th.

‘The wind continuing east with a steady breeze, the current running fast from Sunda Strait; at night we weighed anchor with the wind blowing from the land, set sail and shaped our course so as to pass between the Prince Islands and Cracatouw.’

Leaving Batavia

Leaving Batavia

August 17th.

‘In the morning we had the Prince Islands south-west and Cracatouw north-west by north of us, the wind being south-east, our course south-west by west; at noon we had the southernmost of the Prince Islands east-south-east of us at 5 miles distance, ourselves being in 6° 20′ Southern Latitude and 124° Longitude; in the afternoon we drifted in a calm; in the said afternoon it was resolved that from Sunda Strait we shall sail 200 miles to the south-west by west, as far as 14° South Latitude; from there to the west-south-west as far as 20° South Latitude, and from there due west as far as the island of Mauritius.’

They were underway.

From Krakatoa it was an uneventful journey to Mauritius. They sailed West-South-West until they reached the latitude of 20°S, and then sailed West until they met land. Abel Tasman had fast ships. He completed the 5,500 km crossing of the Indian Ocean at an average of 250 km per day.

September 5th.

‘In the morning we saw that it was the island of Mauritius; we steered for it and came to anchor before it at about 9 o’clock, we being then in Latitude 20°, Longitude 83° 48′. When we saw the island of Mauritius we were by estimation still 50 myles east of it.’

Tasman thought they were still about two days from Mauritius when they sighted land, but in the morning light they recognised the island. He recorded in his journal ‘we were by estimation still 50 myles east of it’ (One Dutch Myle is 7.4km).

Leaving Batavia

Arriving in Mauritius

If we take the longitudes recorded in his log, we see that when Tasman sighted Mauritius he thought he was 41° 51’ west of his departure point. Whereas he was actually 48° 17’ west of Batavia. While he recorded that he was ’50 myles’ short in his estimate, he understated it very significantly indeed. He was actually 91 ‘myles’ awry… that’s 670 km.

There is a huge discrepancy between where he thought he was, and where he actually was.

This highlights the major issue confronting navigators of the day… they had no reliable means of determining their longitude.

Abel Tasman didn’t actually know where he was.

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