@cstrossCharlie Stross Large parts of the new harbour in Aberdeen are made of these things.They called them accropodes.
Not the silicone ones, obviously. The real ones are pretty big and very concrete.
@ravenbaitSam 
@cstrossCharlie Stross Wave-dissipating concrete block enthusiast here, reporting in.
Accropodes are a different type of wave-dissipating concrete block from a tetrapod, and in my expert opinion they are a lot less cuddly:
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