Hollow casings containing a plurality of vertical compartments are towed or floated to an erection site where they are filled with concrete or removable pillar members to form respectively, permanent or temporary columns for supporting drill platforms, piers, etc. First chains or weights are placed in one compartment of a casing to erect it without flooding, and then concrete or removable pillar sections are placed in a second compartment while compressed air is supplied through a third compartment underneath the casing to blow the sand on the bottom of the body of water away to permit the casing to embed itself in the floor of the body of water. Additional concrete or chains, for permanent and temporary columns, respectively, may be added to the several compartments, including that which contained the compressed air line, usually after the removal of the line therefrom, to anchor the column firmly in place.