This apparatus provides an automatic release of a resilient buoyant tether from a water-skimming board device. In use, a tether (100) is attached to a waterboard (50) at one end and secured to an anchor (30) at the other. By maneuvering the board, a rider (20) first stretches the tether and then releases the force stored in the stretched tether to propel the board (50) with rider over the water at high speed. As the board approaches the anchor point (30), the tether (100) automatically releases to reduce drag for an unencumbered ride. When used on a river, the described hook (140) and loop (120) apparatus is easily retrieved by the rider and reconnected to the board (50) in preparation for the next ride. Safety features ensure protection of the rider and of observers. The coupling mechanism may be built in to new water boards or retrofitted to others.