single foot of hydraulic head a vertical array of horizontal chambers disadvantageously requires larger hydraulic head differentials and cannot capture the smaller potential energy increments available in many surf conditions for example the horizontal chambers disclosed in the above cited anderson reference u s pat no 7 040 089 cannot capture significant energy from wave surges of less than two feet moreover instead of the multiple load bearing floors required for a vertical array of horizontal chambers a single load bearing chamber floor is sufficient for this converter embodiment similarly instead of the disadvantageously large amount of air entrainment experienced with a vertical array of horizontal chambers as draining water powers a turbine this converter embodiment entrains a minimal amount of air in water passing through drain assemblies 26 a d plenary conduit 28 turbine 46 and out draft tube 32 to the ambient ocean 30 during operation of this converter embodiment hydraulic head is not lost to backflow as it is in a horizontal chamber array for example when a new wave fills a lower horizontal chamber while it is also receiving drainage from an upper chamber this feature of a vertical array of horizontal chambers causes overtopping of the lower chamber thereby losing captured potential energy to the surrounding ocean during operation of this converter embodiment large volumes of water are reserved in independent chambers and remain available to buffer the continuous flow of water to the conduit and the turbine necessary for stable power output even during a prolonged intermission dry spell between wave surges fig8 9 illustrate a preferred.