Two fixed goatskin heads on a frame contain beads that bounce and roll along the inside surfaces. Sounds like rain and thunder. You can play this drum several ways for multiple sounds.
Create the sounds of the waves breaking, play it like a deff, shake it like a Shakere or beat it like a shaman drum.
To create the sounds of a storm, hold the Drum horizontally. Then roll and gently tilt the drum in all directions. Try different speeds for different sounds. Stop and start suddenly to create crashing sounds.