A breakwater (wave attenuation system) includes two horizontal tubes as buoyant members connected to one another, their cross-sections representing vertices of a triangle, whose legs are interconnecting struts. A perforated, submerged, ballast tube forms the third vertex. Wave motion is perpendicular to the length of the float tubes tethered to an anchor at the sea floor. A lead float tube rises in response to an approaching wave, often cutting off the wave crest, while a trailing float tube rises less and later as the wave passes. Asynchronous rising and falling of the leading and trailing, floating, top tubes rocks the breakwater, redirecting and dissipating wave momentum, energy, and water volume by rotating the assembly, thrashing the water.