In three day eventing, an obstacle that includes a large pool, about 18" deep, into which the horse jumps and gallops out of, usually in landing from an initial obstacle of the jumping effort. In show jumping, an obstacle, usually a shallow water-filled ditch approximately 10-14 feet in length, over which the horse jumps.

A man-made obstacle in the steeplechase usually consisting of a miniature swimming pool containing water up to 70 centimetres deep.