These requirements cover electric luminaires for installation below the surface of the water in swimming pools@ permanently installed spas@ hot tubs@ and similar water-containing vessels intended to accommodate the complete or partial immersion of persons@ and for operation on supply circuits rated 150 volts or less@ in accordance with the National Electrical Code@ NFPA 70. These requirements also cover: a) Metal luminaire housings (forming shells) for use with wet-niche luminaires intended for installation as described in 1.1; b) Mounting brackets for use with no-niche luminaires intended for installation as described in 1.1; and c) Electric luminaires and junction boxes for installation in fountains and similar watercontaining vessels not intended to accommodate the complete or partial immersion of persons. These requirements do not cover junction boxes for use in swimming pools and spas@ ground-fault circuit-interrupters@ transformer enclosures@ or transformers used for the supply of underwater luminaires. Awet-niche luminaire as covered by these requirements is one intended for installation in a metal luminaire housing (forming shell) mounted in or on the wall of a swimming pool or fountain where the luminaire will be surrounded by water. The luminaire is supplied by a flexible cord of sufficient length to permit the luminaire to be removed from the niche and lifted to the deck for servicing. A dry-niche luminaire as covered by these requirements is one intended to be permanently mounted and sealed in the wall of a swimming pool or fountain. It is equipped with provisions for conduit connection@ and is designed to be serviced from the rear in a passageway or tunnel behind the wall or from the deck. A no-niche luminaire as covered by these requirements is one intended for installation on a mounting bracket that is@ in turn@ mounted in or on the wall of a swimming pool or fountain where the luminaire will not extend behind the plane of the wall and will be surrounded by water. The luminaire is supplied by a flexible cord of a length that permits the luminaire to be removed from the mounting bracket and lifted to the deck for servicing.