An alaia (pronounced /ɑːˈlaɪɑː/,[1] Hawaiian: [əˈlɐjjə]) is a thin, round-nosed, square-tailed surfboard ridden in pre-20th century Hawaii. The boards were about 200 to 350 cm (7 to 12 ft) long, weighed up to 50 kg (100 lb), and generally made from the wood of the Koa Tree.[2] They are distinct from modern surfboards in that they have no ventral fins,[1] and instead rely on the sharpness of the edges to hold the board in the face of the wave.
Modern alaias are about 150 to 350 cm (5 to 12 ft) long and are the larger version of the Paipo board, used for knee or belly surfing, and the smaller version of the Olo board, generally between 550 and 750 cm (18 and 24 ft) long. All of these board types are similar in that each is made of wood and is ridden without a sharks fin/skeg.