Abstract: A wave energy device comprising a tube assembly comprising a plurality of open pipes of different lengths and natural resonant frequencies each (FIG. 8) where each tube (13) floating upright in the water (FIG. 2), with the tower end of the tube open to the water and generally disposed below the effective wave base. There is an air column above the water in the tube. Turbine (17) is provided for harnessing power from fluctuations in the air column caused by the changing water level (16) in the tube as a result of the wave motion of the surrounding water (11).