Trail blazers: How charting the sea became lines of desire
Matthew Fontaine Maury's calculations included stark warnings of cyclones and wayward currents. The routes were fragile lines at first but began to thicken as global trade routes were established. Photo / Getty Images
We are now certain of where we are. Three days’ sail west of Vanuatu on a voyage to Cairns, we cross a shipping lane between Australia and China. It is one of many desire lines, or well-worn paths, that criss-cross the Pacific Ocean in a network of trade routes that connect the global economy.
It is rare to see a ship from the deck of a yacht in the vastness of the Pacific, but now there is a steady stream of them along the horizon. As I come up on deck for the first night watch, a log carrier slips across our bow bound for Shanghai. At this distance, there’s no sound, only a dark silhouette and the dim cabin lights in the crew mess, where they are tucking into what smells like a Thai-inspired chicken curry for dinner.
High above our mast, the sweeping arcs of stars carve paths across the sky. Long before the time of log carriers and even Jesus Christ, the Austronesians followed these overhead lines and patterns of the seasons and in doing so they populated the world’s largest ocean. Western navigators took a long time to come to the same realisation as the Austronesians.
It was not until the mid-19th century, after Matthew Fontaine Maury, a midshipman of the United States Navy, had his leg badly broken when the stagecoach he was in overturned, that these paths on the sea began to be documented and compiled in a universal format. It was the beginning of a technological solution that would rationalise its way to solving the mystery of the world’s oceans.
After his accident, Maury was retired from active duties and became head of the Depot of Charts and Instruments, later renamed the US Naval Observatory.
One of the bonuses of his position was access to thousands of ships’ logs and charts archived at the observatory. He scoured the records and began to notice patterns in the winds and currents that repeated themselves throughout the seasons.
In 1850, he published the first of a series of charts under the title of Wind and Current Chart of the North Atlantic. They covered every aspect of the ocean including the migration paths of whales. He then created a uniform system for recording oceanographic data, adopted by navies and merchant marines worldwide.
This system revolutionised modern sea travel and gave it certainty it had never achieved before. Despite its revolutionary nature, all the observation and number crunching were based on circulation patterns that had existed for millennia. The large gyres of the South Pacific and South Atlantic oceans are the result of the persistent pressure of the trade winds and subantarctic westerlies mixed with the Coriolis effect and its ability to bend these into a giant series of oceanic roundabouts. They are the engine room of oceanic circulation, a significant contributor to the planet’s benign climate and were great highways for exploring and trading with the New World.
Although the sea had remained a non-place for much of European history, it became less so when it was realised that crossing it could lead to great riches and the expansion of empires. At various times, the Portuguese, Spanish, Dutch, French and English attempted to dominate the Pacific.
Navigational technology enabled these expansions, with the sextant, chronometer and compass at the forefront, but it was Maury’s pilot books that were the final critical piece in the puzzle. They gave foreknowledge: the ability to guess the best way to go and what tomorrow might bring.