Abstract: In the centers of each of unit-type lenses that constitute a lens, a plurality of elliptically light distributing LEDs being arranged circularly in a horizontal direction in such a way that a wider divergence angle of each LED is set to be oriented horizontally. The unit-type lenses are stacked and fastened by a screw that runs through the bosses of the unit-type lenses.

Abstract: A spar buoy is so arranged that a buoyancy body (1) is provided halfway on a marker mast (2), the lower end of the marker mast (2) being moored to a sinker (7) sunk at water bottom by a mooring device (6) and that the buoyancy body 1 is pulled in the water so that the water line comes to halfway on the marker mast (2) above the buoyancy body (1), the spar buoy comprising at least two arms (8, 8) protruded in opposite directions to each other from the marker mast (2) below the buoyancy body (1), and blades (9, 9) attached to the end of each arm (8) so as to have a positive angle of attack .alpha. toward the center of the buoy.

Abstract: A beacon lantern and a lens for the same with improved light transmission factor, which is easy to manufacture and uses LEDs as a light source. A lantern comprising light source of many LEDs radially distributed on a horizontal circumference and a cylindrical fresnel lens converging beams of light in all horizontal directions, in which the lens is made by rolling a sheet-like, fine prism-shaped linear fresnel lens into a shape of a cylinder. The lantern maintains a top lid and a lower lantern body with a prescribed distance therebetween by way of a center bolt, between said lid and lower lantern body a transparent cylindrical cover is maintained, on the inner surface thereof is the rolled sheet-like linear fresnel lens joined therewith.