Abstract: An improved, explosively embedded anchor assembly for use in sedimentary strata and similarly nonconsolidated or rocky ocean bottom surfaces is shown. The anchor comprises an inertially loaded reaction member above a substantially elongated anchor shaft, coaxially positioned around an elongated drive tube assembly. The anchor shaft has a number of open cross-section triangular sheet metal anchoring fins, providing substantially low resistance to penetration within the strata, but providing substantially high resistance to sideways displacement forces, as would be imposed through a standard anchor rode. The anchor is positioned by lowering the inertial reaction unit and embedded by the weight of the inertial reaction unit a distance into the surface layer of the subocean strata. An internal detonator control assures vertical embedment unless the anchor is vertically positioned. The anchor is remotely fired after initial embedment.