Head for bang, on the southwest edge of Sumba. Then 2km down the hill towards Kallala. The breaks are just outside the village. The accommodation in Waingap can sort out your transport although roads are sketchy. You can stay in one of 6 bungalows on the beach.
east coast waves that are offshore in the dry season, courtesy of a pronounced nose of land fringed by a large protuberant reef that arcs down to the south.