An adjustable pulley device which resides on a boat's anchor rope, which, when the anchor has been set offshore, allows an operator to pull the boat from shore to a pre-determined point on the anchor rope, and retrieve it. It comprises a housing with an integral pulley sheave and rope arresting mechanism in conjunction with a snap shackle which is tethered to the boat. To use the device, the snap shackle is snapped around the anchor rope between the sheave and the arresting mechanism on the device. As the boat approaches the shore, the anchor is put over side, and with the anchor set, the anchor rope slides through the device and shackle until the arresting mechanism is actuated. The device, now attached to the anchor rope, becomes the turning block which in conjunction with the shackle make up a pulley system to move the boat to and from shore.