46 CFR §183.372

1. (a)All metallic enclosures and frames of electrical equipment must be permanently grounded to the hull on a metallic vessel. On a nonmetallic vessel, the enclosures and frames of electrical equipment must be bonded together to a common ground by a normally non-current carrying conductor. Metallic cases of instruments and secondary windings of instrument transformers must be grounded.
2. (b)On a nonmetallic vessel, where a ground plate is provided for radio equipment, it must be connected to the common ground.
3. (c)Equipment grounding conductors must be sized in accordance with Section 250-96 of NFPA 70 (incorporated by reference; see 46 CFR 175.600), or other standard specified by the Commandant.
4. (d)Each insulated grounding conductor of a cable must be identified by one of the following means:
   1. (1)A green braid or green insulation;
   2. (2)Stripping the insulation from the entire exposed length of the grounding conductor; or
   3. (3)Marking the exposed insulation of the grounding conductor with green tape or green adhesive labels.
5. (e)Cable armor must not be used to ground electrical equipment or systems.