Abstract: A mooring device for use, particularly in the mooring of an aircraft such as a helicopter on the deck of a ship includes a grid having an upper surface adapted for engagement by a harpoon carried by the aircraft. The grid comprises a plurality of substantially identical elements and retaining means secured to the deck and adapted to retain the elements in juxtaposed relationship. In one embodiment the elements are generally rectangular in plan and have an upper surface provided with both full and half apertures arranged so that when in said juxtaposed relationship, the elements combine to provide a generally continuous apertured upper surface.