Coral rock walls are made from once-living organisms that were made to breath. Once sealed however, the coral rock seawall is much less porous and requires weep holes to be installed in the the wall to allow water flow in and out, which reduces hydro-static pressure.
Coral rock seawalls, while naturally beautiful, require quite a bit of maintenance and will need to be repaired every two to four years. Coral rocks stacked in a pyramid move naturally due to vibration and other natural forces. Cracks must be mudded and maintenance is required to conserve soil on your property. Soil should be kept at the height of the seawall cap so rain water can run off the cap and not behind the wall, which will create unwanted hydro-static pressure and may damage your coral wall.