as illustrated in fig1 and 2 average concrete thickness is about 6 inches and each module weighs about 4200 pounds modules 11 are to be placed side by side in groups of 8 to 15 more or less with passages betweeb each group groups are to be placed in the surf zone in water 3 to 4 feet deep at mean high tide wave overlapping occurs from wave action and storm surge 21 toe scour does not occur either on the beach side or the seaward side of the modules and sediment 22 gradually accretes on both seaward and landward sides actual burial of the module groupings can occur under optimum conditions modules of the design described can be placed offshore by helicopter modules of different sizes can of course be used the modules which are preferably right angled prisms may be placed in side by side relationship with their respective seaward faces in substantial alignment in consideration of the cost of an offshore installation as contemplated by the invention high standards should be observed in pouring the modules in particular corrosion resistant reinforcement such as pre stressed polypropylene synthetic fibers and epoxy coated reinforcing bar should be used in ample and appropriate amounts concrete having a strength of 5000 psi with a slump of 3 inches made using type 5 cement and 4 air entrained with pozzolan should be used generous chamfer should be provided for all edges with quality construction modules in accordance with the invention will last 50 years even in salt water while modules groupings may be placed substantially parallel to the.