Abstract: A support arm is provided including base and outer ends and mounting structure is provided on the base end for mounting the support arm from a boat in a generally horizontally disposed position with the outer end of the support arm projecting outwardly of one side portion of the boat. The outer end of the support arm structure is bifrucated to provide an endwise outwardly opening vertical slot and the support arm includes outer end downwardly projecting and inwardly curving guide structure. Flexible tension member guide structure is mounted on the outer end of the support arm above the slot and guidingly receives an elongated flexible tension member extending generally lengthwise of the support arm. One free end portion of the flexible tension member depends downwardly through the slot and is equipped with anchor member attaching structure on its lower free end.