The Charting of the Red Sea

The Red Sea has been described as a sea on its way to somewhere else. In other words its shores were not lined with valuable commodities waiting to be exported; instead it was an essential link between the two great commercial zones of the Mediterranean/ European world and that of the Indian Ocean. In the nineteenth century this treacherous sea would come to play a key role in a new era of communication between industrial Britain, with its rapidly expanding economy, and British India, with its raw materials and imperial requirements. Crucial in the development of the Red Sea route between the two countries was the harnessing of steam power, most notably in the form of the marine steam engine. But a further vital factor in this revolution in trade and transport was the charting of the hazardous waterway commissioned by the British East India Company and carried out by the little-known naval commander Robert Moresby and his colleague Thomas Elwon, both of the Bombay Marine, later the Indian Navy. Moresby, thought to have died in 1863, is a figure who has now all but disappeared from the records. But his feat in charting the dangerous waters of the Red Sea in the 1820s and 30s, ensured the route was viable for the new steam vessels.

From Suez at the northern end to the Bab al-Mandab at the southern end, the Red Sea is about 2,350 kilometres long, with an average width of 200 kilometres. At the Bab al-Mandab at the southern end it is a mere 30 kilometres wide. At the northern end it divides into two narrower waterways: the main one, the Gulf of Suez, is 300 kilometres long, the narrow, storm-tossed Gulf of Aqaba 180 kilometres long. According to the Admiralty’s Red Sea Pilot , coral reefs are ‘more numerous and more extensive than in any other body of [equal] water’. Long strips of reef run parallel to the shore a few feet below the surface. Gaps in the reef lead to inshore channels that are sheltered and deep, and these are used by local vessels today as they were by the small-paddle steamers of the 1830s. In daylight a careful eye can distinguish reefs by changes in the colour of the water, though this is more difficult in summer when reefs can be confused with a brown scum of seaweed. There are also numerous coral islands, such as the Farasan archipelago off the Arabian coast near Jizan or the Dahlak archipelago off Massawa, as well as volcanic out-crops such as the Zubayr islands off Yemen.