Common Marine Wire and Boat Cable Approvals

UL 1426

UL 1426 is a commonly seen marine specification for electrical cables. Marine wire that has been investigated by the Underwriters Laboratories will meet the requirements of UL 1426. UL 1426 is the numerical standard referenced in UL's BDFX reference for boat cable. The (BDFX) Boat Cable guide reads, "Boat cable is rated 600 V or less, 60 ºC or 75 ºC wet, 60 ºC to 200 ºC in dry locations and, for cable so marked, 60 ºC and lower temperatures where exposed to oil. The cable employs stranded copper conductors in a size range of 18 to 4/0 AWG inclusive for multi-conductors, 16 to 4/0 AWG inclusive for single conductors."

Marine wire, boat cable, and marine primary wire that meet UL 1426 approval will be marked accordingly. The markings you should search for on a UL 1426 approved wire will be "UL 1426," "Boat Cable," or "BC5-W2." The UL requires the marking to be printed on the electrical cable.

UL 1426 approved electrical cable may be used on marine pleasure craft and is widely accepted for marine cable installed in recreational boats. Many US built boats have cables that comply with the standard.


BC-5W2 is another marine specification. It is a heat rating designation on UL 1426 (105 ºC in a dry environment, 75 ºC in a wet environment). The term "boat cable" may sometimes be a specific term used in certain cases to indicate the BC-5W2 approved wire. BC-5W2 is suitable for use on boats and non-commercial marine vessels.