Abstract: An apparatus for securing a watercraft in spaced apart relation to a mooring facility, including but not limited to docks. The apparatus controls horizontal movement of the watercraft, but allows free vertical movement with the rise and fall of the water supporting the watercraft. The apparatus comprises a longitudinal beam that is attached to the dock in a generally vertical orientation and a channel member that is slidably carried by the beam. A first arm and a second arm are longitudinally joined by a flexible connector and the free end of the first arm is attached to the channel member. The apparatus further comprises a guide comprising a fender and a longitudinal element that extends therefrom. The free end of the longitudinal element is attached to the free end of the second arm and a clamp is adjustably attached to the element. The clamp has structure thereon for attaching the clamp to a water craft.