African Water Drums are large hollow gourds cut in half and filled with water. Smaller gourds also cut in half sit on top of the water open end down. When the smaller gourds are played with the hands or soft mallets they create a unique bass tone. A cracking sound can be made by striking the sides of the larger water-filled gourds. These drums were traditionally played by women in many African tribes.
In modern times, plastic bowls are sometimes used to float on top of the water. My friend (and Yellow Bell musician) Ken Benjamin demonstrates in the photo to the right.
Hear the Water Drums on 'Rain Trance' from 'Rain Trance'.