Abstract: A tubular shank structure the anchor includes an elongate arm control member which moves lengthwise within a main body of the shank structure. Pivotally mounted arm members may be maintained collapsed along side the anchor shank structure or may be operatively held perpendicular to the shank structure by the arm control member. Upward positioning of the arm control member causes same to disengage the arm member ends to permit the arm members to rotate downwardly relative the shank structure so as to disengage an underwater obstruction. An anchor line is secured to the shank structure by a breakaway tie which, in case of anchor fouling, may be ruptured to permit positioning of the arm control member for anchor release.