bolts are countersunk relative to the inner surface of the bumper to avoid contact between the bolts and the spar tube shims 32 may be interposed between the bumper and the top cap the shims are made of composite material and have slots that allow them to be fitted over the bolts that attach the bumper to the top cap by selecting shims of appropriate thickness the inner surfaces of the bumpers can be positioned with sufficient precision on a circle of a desired radius that allows a small clearance between the bumpers and the spar without need to machine the cylindrical portion of the top cap in similar fashion a lower set of twelve bumpers is attached to the shell about the interior opening defined by the bottom cap 246 the float also comprises an annular permanent magnet assembly 34 located between the top and bottom caps in the opening defined by the inner wall of the shell the nature of the permanent magnet assembly depends on the design of the linear generator the radial position of the inner surfaces of the bumpers is selected to provide proper positioning of the permanent magnet assembly relative to the spar tube in order to minimize friction between the bumpers and the spar and maximize electrical efficiency of the generator the outer surface of the spar tube may be machined at least over the movement range of the float to a smoothness of astm 150 use of composite material for fabrication of the wave energy buoy described with.