Lateen

The earliest fore-and-aft rig was the spritsail, appearing in the 2nd century BC in the Aegean Sea on small Greek craft.[2] The lateen sail originated somewhat later during the Roman empire in the Mediterranean Sea.[2][3][4][5][6][7][8][9][10][11][12] It evolved out of the dominant square rig by setting the sails more fore-and-aft – along the line of the keel – rather than athwartship, while tailoring the luff and leech.[13]

Byzantine ship rigged with settee sail (miniature from c. 880)[14]

Both types of lateen were likely used from an early date on: a 2nd-century AD gravestone depicts a quadrilateral lateen sail (also known as a settee), while a 4th-century mosaic shows a triangular one which was to become the standard rig throughout the Middle Ages.[2] According to the Belgian maritime historian Lucien Basch, the true lateen rig appears as early as the 1st century BC, in a Hellenistic wall painting found in a Hypogeum in Alexandria.[15] The earliest archaeologically excavated ship that has been reconstructed with a lateen rig is dated to ca. 400 AD (Yassi Ada II), with a further four being attested prior to the Arab advance to the Mediterranean.[16] The Kelenderis ship mosaic (late 5th to early 6th century)[17][18] and the Kellia ship graffito from the early 7th century complement the picture.[18]

By the 6th century, the lateen sail had largely replaced the square sail throughout the Mediterranean, the latter almost disappearing from Mediterranean iconography until the mid-13th century.[19] It became the standard rig of the Byzantine dromon war galley and was probably also employed by Belisarius' flagship in the 532 AD invasion of the Vandal kingdom.[15][20] The fully triangular lateen and the settee continued to coexist in the middle Byzantine period, as evidenced by Christian iconography,[14] as well as a recent find of a graffito in the Yenikapı excavations.[21] In the 12th to 13th centuries the rigging underwent a change when the hook-shaped masthead made way for an arrangement more akin to a barrel-like crow's nest.[22]

After the Muslim conquests, the Arabs adopted the lateen sail by way of the Coptic populace, which shared the existing Mediterranean maritime tradition and continued to provide the bulk of galley crews for Muslim-led fleets for centuries to come.[23] This is also indicated by the terminology of the lateen among Mediterranean Arabs which is derived from Greco-Roman nomenclature.[24] More detailed research into their early use of the lateen is hampered by a distinct lack of unequivocal depictions of sailing rigs in early Islamic art.[25] A glazed pottery dish from Saracenic Dénia dating to the 11th century is at present the earliest securely identifiable example found in the Mediterranean.[25]

From the Mediterranean, the lateen sail spread to the Nile River in Egypt, where the lateen-rigged felucca was developed.[26]

Dhow with lateen sail in "bad tack" with the sail pressing against the mast, in Mozambique.

The emergence of new evidence for the development and spread of the lateen sail in the ancient Mediterranean in recent decades has led to a reevaluation of the role of Arab seafaring in the Indian Ocean in that process. Neither the attribution of the lateen to the Arabs nor its origin in the Indian Ocean can any longer be upheld:

The origin of the lateen sail has often been attributed by scholars to the Indian Ocean and its introduction into the Mediterranean traditionally ascribed to the Arab expansion of the early-7th century. This was due mainly to the earliest (at that time) iconographic depictions of lateen rigged ships from the Mediterranean post-dating the Islamic expansion into the Mediterranean basin...It was assumed that the Arab people who invaded the Mediterranean basin in the 7th century carried with them the sailing rig familiar to them. Such theories have been superseded by unequivocal depictions of lateen-rigged Mediterranean sailing vessels which pre-date the Arab invasion.[27][28]

A large dhow with two settee sail rigs and a headsail.

Further inquiries into the appearance of the lateen rig in the Indian Ocean and its gulfs show a reversal of earlier scholarly opinion on the direction of diffusion, now pointing to an introduction by Portuguese sailors in the wake of Vasco da Gama's arrival in India in 1500.[29] Searches for lateen sails in India were inconclusive.[30] Since lateen sails were absent from Indian inland waters, that is in regions remote from foreign influences, as late as the mid-20th century, the hypothesis of an Indian origin appears a priori implausible.[31] The earliest evidence for the lateen in Islamic art adjacent to the Indian Ocean occurs in a 13th-century Egyptian artifact which, however, is assumed to show a Mediterranean vessel.[32] Excavated depictions of Muslim vessels along the Eastern African coast uniformly show square sails before 1500.[33] A recent discovering of a pot shred from Srilanka dating back to 3nd century BC shows triangular sail on a rigger.[34][35] A terracotta seal from Chandraketugarh according to J. Deloche may represent furled lateen sail.[36] Boats depicted in Chamardi rock cave painting dated to Maitraka dynasty from 5th century-7th century AD (but sometimes dated as late as 10th, 12th or 14th century) provides evidence of two Kotiya ships with lateen sail also with mounted rudder.[37] Fore and aft sail has also been depicted in Ajantha ship painting of 6th century AD.[38] According to archaeologist Daniel T Potts, An iron age pendant from Tell Abraq also shows one of the earliest depiction of lateen sails dated 1000-500 BC[39]

After 1500, the situation in the Indian Ocean dramatically changed, with nearly all vessels now being lateen rigged.[32] As Portuguese hull design and construction methods are known to have been subsequently adopted by Eastern Muslim shipbuilders, it is assumed that this process also included the lateen rigging of the novel caravel.[40] Within fourteen years of da Gama's arrival, lateens were spotted by the Portuguese on local vessels.[40]

Lateen-rigged caravel, the main vessel of the Portuguese long-distance explorations

A 17th-century woodcut of a triangular-sailed Bermudian vessel. Its raked masts were a development of the lateen.

Until the 14th century, the lateen sail was employed primarily on the Mediterranean Sea, while the Atlantic and Baltic (and Indian Ocean) vessels relied on square sails. The Northern European adoption of the lateen in the Late Middle Ages was a specialized sail that was one of the technological developments in shipbuilding that made ships more maneuverable, thus, in the historian's traditional progression, permitting merchants to sail out of the Mediterranean and into the Atlantic Ocean; caravels typically mounted three or more lateens. However, the great size of the lateen yardarm makes it difficult and dangerous to handle on larger ships in stormy weather, and with the development of the carrack, the lateen was restricted to the mizzen mast. In the early nineteenth century, the lateen was replaced in European ships by the driver or spanker.

The lateen survived as a rigging choice for mainsails of small craft where local conditions were favorable. For instance, barge-like vessels in the American maritimes north of Boston, called gundalows, carried lateen rigs throughout the late nineteenth and early twentieth centuries. Likewise, lateen sail survived in the Baltic until the late 19th century. Because the yard pivots on its point of attachment to the mast, the entire sail and yard can be swiftly dropped. This was an advantage when navigating the tidal riverways of the region, which often required passage under bridges. The balancelle, a Mediterranean coasting and fishing boat of the 19th century, also used a single lateen sail.

One of the disadvantages of the lateen in the modern form described below is the fact that it has a "bad tack". The sail is to the side of the mast, on one tack that puts the mast directly against the sail on the leeward side, where it can significantly interfere with the airflow over the sail. On the other tack the sail is pushed away from the mast, greatly reducing the interference. On modern lateens, with their typically shallower angles, this tends to disrupt the airflow over a larger area of the sail.

However, there are forms of the lateen rig, as in vela latina canaria, where the spar is changed from one side to the other when tacking. This way the rig doesn't suffer these airflow disruptions that come from the sail pushed against the mast.[41]

The lateen sail can also be tacked by loosening the yard upper brace, tightening the lower brace until the yard is in vertical position, and twisting the yard on the other side of the mast by a tack. Another way of tacking with a lateen sail is to loosen the braces, lift the yard vertical, detach the sheet and tack, and turn the sail on the other side of the mast in front of the mast, and reattach the sheet and tack. This method is described in Björn Landström's The Ship.

The lateen rig was also the ancestor of the Bermuda rig, by way of the Dutch bezaan rig. In the 16th century, when Spain ruled the Netherlands, the lateen rigs were introduced to Dutch boat builders, who soon modified the design by omitting the mast and fastening the lower end of the yard directly to the deck, the yard becoming a raked mast with a full-length, triangular (leg-of-mutton) mainsail aft. Introduced to Bermuda early in the 17th century, this developed into the Bermuda rig, which, in the 20th century, was adopted almost universally for small sailing vessels.