During factory and boat show inspections we have observed that many manufacturers of recreational boats do not have a good understanding of the navigation rules governing proper installation of navigation lights. The problem appears to be particularly prevalent for manufacturers located in the western States. Since most manufacturers routinely equip the boats they produce with navigation lights, navigation light installations are routinely inspected and discussed during factory visits and boat shows. One problem which has increased recently is the installation of flush mounted sidelights in the boat hulls, usually below the rub rail.
Many manufacturers build boats using similar sidelight fixture installations.
This is a dangerous trend which is likely to end up costing somebody a pile of money when a plaintiff's attorneys go after everyone who might have been for liable for a serious collision. Sidelights which meet the rules are designed to cover an arc of the horizon, or sector, of 112.5 degrees. These fixtures are designed for intensities to decrease and reach practical cutoff between 1 and 3 degrees outside their prescribed sector. Sidelight fixtures must be installed parallel with the fore and aft centerline of the vessel and arranged to show an unbroken light from right ahead to 22.5 degrees abaft the beam, a total sector arc of 112.5 degrees. Sidelights that are installed in the contour of the bow without providing a mounting surface tooled to be parallel with the fore and aft centerline of the vessel are not in compliance with the Inland or International Navigation Rules.