An anchor has a fluke, a shank that is connected to the fluke, a coupling to attach the fluke to an anchor line or anchor chain, and an angle adjustment provision to adjust the angle between the shank and the fluke, wherein the angle adjustment provision is a hinge between the fluke and the shank, a first positioning member connected to the shank that is provided with a series of first positioning holes at a first intermediate distance and a second positioning member connected to the fluke that is provided with a series of second positioning holes at a second intermediate distance and spaced apart from the hinge axis, and a positioning pin that is inserted in one of the aligned first and second positioning holes, wherein the second intermediate distance differs from the first intermediate distance.