46 C.F.R. § 120.410 – Lighting fixtures.

(a) Each lighting fixture globe, lens, or diffuser must have a guard or be made of high strength material, except in an accommodation space, radio room, galley, or similar space where it is not subject to damage.
(b) A lighting fixture may not be used as a connection box for a circuit other than the branch circuit supplying the fixture.
(c) A lighting fixture must be installed as follows:
1. (1) Each fixture must comply with § 120.200.
2. (2) Each lighting fixture and lampholder must be fixed. A fixture must not be supported by the screw shell of a lampholder.
3. (3) Each pendant type lighting fixture must be suspended by and supplied through a threaded, rigid conduit stem.
4. (4) Each table lamp, desk lamp, floor lamp, or similar equipment must be secured in place so that it cannot be displaced by the roll or pitch of the vessel.
(d) An exterior lighting fixture in an electrical system operating at more than 50 volts must comply with the requirements of UL 595, “Marine Type Electric Lighting Fixtures,” or other standard specified by the Commandant. A lighting fixture in an accommodation space, radio room, galley or similar interior space may comply with, UL 1570, “Fluorescent Lighting Fixtures,” UL 1571, “Incandescent Lighting Fixtures,” UL 1572, “High Intensity Discharge Lighting Fixtures,” UL 1573, “Stage and Studio Lighting Units,” or UL 1574, “Track Lighting Systems,” as long as the general marine requirements of UL 595 are satisfied.