The Kerala houseboat — the kettuvallam — was originally a rice barge: a long thatched-roof boat tied together with coir rope instead of nails, used to move rice from the polders to the coastal markets. From the 1990s the surplus boats were converted to floating hotels, and today several thousand of them work the backwaters of central Kerala.
A typical Kumarakom trip takes you out across the lake, into the smaller canals around the bird sanctuary, and along the rice polders behind the village. A standard cruise lasts 24 hours: lunch on board, mooring overnight, dawn paddle, breakfast, return next morning. Food is good — fresh fish from the lake, coconut, rice, plenty of curry leaves. Day trips are also possible. Book through the homestay or via the Alleppey/Kumarakom houseboat cooperative offices on the lake's edge.