Houseboats in Kerala, south India, are huge, slow-moving barges used for leisure trips. They are a reworked model of Kettuvallams (in the Malayalam language, Kettu means "tied with ropes", and vallam means "boat"), which, in earlier times, were used to carry rice and spices from Kuttanad to the Kochi port.
These have thatched roof covers over wooden hulls. The traditional kettuvallam is mainly used for promoting Kerala tourism