structural:scholar_edition
Ships and sailing

Seagoing catamaran and outrigger ship technologies were the most important innovations of the Austronesian peoples. They were the first humans with vessels capable of crossing vast distances of water. The crossing from the Philippines to the Mariana Islands at around 1500 BCE, a distance of more than 2,500 km (1,600 mi), is likely the world's first and longest ocean crossing of that time. These maritime technologies enabled them to colonize the Indo-Pacific in prehistoric times. Austronesian groups continue to be the primary users of outrigger canoes today.

Early researchers like Heine-Geldern (1932) and Hornell (1943) once believed that catamarans evolved from outrigger canoes, but modern authors specializing in Austronesian cultures, like Doran (1981) and Mahdi (1988), now believe it to be the opposite.

Two canoes bound together developed directly from minimal raft technologies of two logs tied together. Over time, the double-hulled canoe form developed into the asymmetric double canoe, where one hull is smaller than the other. Eventually the smaller hull became the prototype outrigger, giving way to the single outrigger canoe, then to the reversible single outrigger canoe. Finally, the single outrigger types developed into the double outrigger canoe (or trimarans).

This would also explain why older Austronesian populations in Island Southeast Asia tend to favor double outrigger canoes, as it keeps the boats stable when tacking. However, there are small regions where catamarans and single-outrigger canoes are still used. In contrast, more distant outlying descendant populations in Micronesia, Polynesia, Madagascar, and the Comoros retained the double-hull and the single-outrigger canoe types, but the technology for double outriggers never reached them (although it exists in western Melanesia). To deal with the problem of the boat's instability when the outrigger faces leeward when tacking, they instead developed the shunting technique in sailing, in conjunction with reversible single-outriggers.

The simplest form of all ancestral Austronesian boats had five parts. The bottom consisted of a single piece of hollowed-out log. At the sides were two planks, and two horseshoe-shaped wood pieces formed the prow and stern. These were fitted tightly together edge-to-edge, with dowels inserted into holes in between, and then lashed to each other with ropes (made from rattan or fibre) wrapped around protruding lugs on the planks. This characteristic and ancient Austronesian boatbuilding practice is known as the " lashed-lug " technique. They were commonly caulked with pastes made from various plants as well as tapa bark and fibres that would expand when wet, further tightening joints and making the hull watertight. They formed the shell of the boat, which was then reinforced by horizontal ribs. Shipwrecks of Austronesian ships can be identified from this construction as well as the absence of metal nails. Austronesian ships traditionally had no central rudders but were instead steered using an oar on one side.

The ancestral rig was the mastless triangular crab claw sail, which had two booms that could be tilted to the wind. These were built in the double-canoe configuration or had a single outrigger on the windward side. In Island Southeast Asia, these developed into double outriggers on each side, which provided greater stability. The triangular crab claw sails also later developed into square or rectangular tanja sails, which, like crab claw sails, had distinctive booms spanning the upper and lower edges. Fixed masts also developed later in both Southeast Asia (usually as bipod or tripod masts) and Oceania. Austronesians traditionally made their sails from woven mats of the resilient and salt-resistant pandanus leaves. These sails allowed them to embark on long-distance voyaging. In some cases, however, they were one-way voyages. The failure to establish populations in Rapa Nui and New Zealand is believed to have isolated their settlements from the rest of Polynesia.

The ancient Champa of Vietnam also uniquely developed basket-hulled boats whose hulls were composed of woven and resin -caulked bamboo, either entirely or in conjunction with plank strakes. They ranged from small coracles (o thúng) to large oceangoing trading ships like the ghe mành.

The acquisition of catamaran and outrigger technology by non-Austronesian peoples in Sri Lanka and southern India is due to the result of very early Austronesian contact with the region, including the Maldives and the Laccadive Islands, estimated to have occurred around 1000 to 600 BCE and onwards. This may have possibly included limited colonization by people who have since been assimilated. This is still evident in Sri Lankan and South Indian languages. For example, Tamil paṭavu, Telugu paḍava, and Kannada paḍahu, all meaning "ship", are all derived from Proto-Hesperonesian *padaw, "sailboat", with Austronesian cognates like Sundanese parahu, Javanese perahu, Kadazan padau, Maranao padaw, Cebuano paráw, Samoan folau, Hawaiian halau, and Māori wharau.