A marine anchor having a shank connectible to an anchor rode at one end and having a double ploughshare fluke rigidly mounted at the other end thereof is described. The fluke consists of two symmetrically mounted part-cylindrical blades disposed on each side of a central ridge in the medial plane of the shank and extending from a forward apex to divergent trailing ends. A ballast weight is mounted under the convex surfaces of the blades and contained within the tangential plane to the convex surfaces. Each blade is also provided with a fin along the outer edge thereof, perpendicular to the central edge and located aft of the junction of the shank and the fluke.
An asymmetric boat anchor has an unballasted fluke (2), with a tip (6) and a back (8) with a curved edge (10); a shank (4) is mounted on the fluke. The edge (26) of the shank away from the tip (6) of the fluke is curved and the free end of the shank (18) is offset from a plane (30) tangent to the back edge (10) of the fluke and to the edge (26) of the shank. Thus, if the anchor is in a reverse position, contacting the sea ground through the edge of the shank and the back edge of the fluke, it will roll on the edge of the shank and turns to the anchoring position.