The invention comprises an anchor including a shank which in cross section along at least part of its length has forward and rearward facing edges and a pair of side faces between said edges. The parts of the shank adjacent the forward edge are substantially “v” shaped in cross section and at least part of the side faces between the edges are concave. The anchor further includes a fluke having a forward end and a rearward edge in normal use, the rearward edge having a continuous flange extending therefrom over at least a substantial part of the rearward edge. The anchor has a roll-bar positioned substantially above the upper surface of the fluke forming a semi-circular wheel spanning the width of the fluke and wherein along at least a substantial part of its length the roll-bar is in cross section substantially in the form of a foil.