Sea lanes

A sea lane, sea road or shipping lane is a regularly used route for vessels on oceans and large lakes. In the Age of Sail they were not only determined by the distribution of land masses but also the prevailing winds, whose discovery was crucial for the success of long voyages. Sea lanes are very important for trade by sea.

The establishment of the North Atlantic sea lanes was inspired by the sinking of the US mail steamer SS Arctic by collision with the French steamer SS Vesta in October 1854 which resulted in the loss of over 300 lives. Lieutenant M. F. Maury of the US Navy first published a section titled "Steam Lanes Across the Atlantic" in his 1855 Sailing Directions proposing sea lanes along the 42 degree latitude. A number of international conferences and committees were held in 1866, 1872, 1887, 1889, and 1891 all of which left the designation of sea lanes to the principal trans-Atlantic steamship companies at the time; Cunard, White Star, Inman, National Line, and Guion Lines. In 1913–1914 the International Convention for Safety of Life at Sea held in London again reaffirmed that the selection of routes across the Atlantic in both directions is left to the responsibility of the steamship companies.

Shipping lanes came to be by analysing the prevailing winds. The trade winds allowed ships to sail towards the west quickly, and that the westerlies allowed ships to travel to the east quickly. As such, the sea lanes are mostly chosen to take full advantage of these winds. Currents are also similarly followed as well, which also gives an advantage to the vessel.

Some routes, such as that from Cape Town to Rio de Janeiro (passing Tristan da Cunha), weren't able to take advantage of these natural factors.

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