Abstract: A lighting device comprises a waterproof housing in the form of an elongated flattened tube of substantially uniform transverse cross section that encloses a plurality of parallel tubular fluorescent lamps positioned lengthwise in the housing. The housing has two substantially parallel face walls of relatively large area and two connecting walls of relatively small area, at least one of the two substantially parallel face walls being transparent. The housing further comprises a watertight closed end and an open end having a rim that corresponds to the cross section of the housing at that end. A removable watertight cap covers the open end of the housing, the underside of the cap having a circumferential groove corresponding to the rim of the housing, and a gasket is positioned in the groove. The cross section of the housing is elongated transversely and is indented at each end thereof to form a lengthwise groove in the outer surface of each of the connecting walls of the housing.