Picture a floating breakwater design. It is not intended for occupation. It would be a pure breakwater, potentially it could have a dual purposes for freshwater storage, but this would be somewhat complex.
It is massive, and therefore expensive. It is not very mobile. It is turret-moored, in a sense. Rather than the turret rotating around a vertical access, it has dual turrets, one on each end with a horizontal axis. This limits the number of catenary anchor lines possible, perhaps to three on each turret. The massive body of the breakwater is allowed to "roll" in response to swells, which makes it dissipate some of the energy. It absorbs some and dissipates it through gravity/displacement heaving. The varying angles of the multiple faces of the breakwater both engage the swells more fully and cause the swell to break across the length at different times. Although pictured as a star-shaped cylinder here, it could be a spiral, or have a number of different armatures of various length and internal buoyancy, as complex as is financially feasible.