Ngahau. Bow. A ngahau (bow) is one of the most basic weapons and hunting implements in Tonga, it is also known as a kaufana. This ngahau has been carved from one block or branch of wood, most probably the toa (ironwood) tree. It is medium brown in colour and smooth and polished along the entire surface, there is a indentation along the length that ends in a notched point at either end. It is a curved bow which is used for close range shooting, ngahau can be used as a weapon in times of warfare as well as hunting on both land and sea.