Austronesian vessels
[2] They also include indigenous ethnic minorities in Vietnam, Cambodia, Myanmar, Thailand, Hainan, the Comoros, and the Torres Strait Islands.
Traditional sail types include a variety of distinctively Austronesian crab-claw and tanja configurations, though modern vessels are typically motorized.
These were fitted tightly together edge-to-edge by sewing or 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.
They were commonly caulked with pastes made from various plants as well as tapa bark and fibres which would expand when wet, further tightening joints and making the hull watertight.
They are used throughout the range of the Austronesian Expansion, from Maritime Southeast Asia, to Micronesia, Island Melanesia, Polynesia, and Madagascar.
[11] Austronesian rigs were used for double-canoe (catamaran), single-outrigger (on the windward side), or double-outrigger boat configurations, in addition to monohulls.
In addition to the unique invention of outriggers to solve this, the sails were also leaned backwards and the converging point moved further forward on the hull.
This new configuration required a loose "prop" in the middle of the hull to hold the spars up, as well as rope supports on the windward side.
This allowed more sail area (and thus more power) while keeping the center of effort low and thus making the boats more stable.
[11][12] Micronesian, Island Melanesian, and Polynesian single-outrigger vessels also used the canted mast configuration to uniquely develop shunting.
The crab claw configuration used on these vessels is a low-stress rig, which can be built with simple tools and low-tech materials, but it is extremely fast.
The lower part of two of the bamboo poles of the mast assembly have holes that are fitted unto the ends of a cross-wise length of timber on the deck, functioning like a hinge.
[16] The sail can be rotated around the mast (lessening the need for steering with the rudders) and tilted to move the center of pull forward or aft.
