In one aspect, a mat for placement on a sea floor includes a plurality of fabric cells formed from a first fabric layer and a second fabric layer, each of the plurality of fabric cells including a first cell edge and a second cell edge where the first and second fabric layer are coupled, the first and second cell edges being aligned in a first direction, a third cell edge and a fourth cell edge where the first and second fabric layer are coupled, the third and fourth cell edges being aligned in a second direction and a cavity configured to receive a filling material, the cavity being defined by the first, second, third and fourth cell edges. The mat also includes a grid of cables disposed within and supporting the plurality of fabric cells.