Don Casey has put together an excellent overview of basic marine electrical common sense that is well worth checking out. His piece, Electrical Connections, serves as a good introduction to a number of boat wiring issues.

In the article, Mr. Casey makes a very strong case for the use of tinned wire…

The wire must be copper, but even copper corrodes in the marine environment, and corrosion is the  primary cause of electrical failures on a boat.

Plating each strand of the wire with a thin coat of tin–called tinning–dramatically improves corrosion resistance. The additional cost of tinned wire is nominal, the benefits substantial. Under normal circumstances use only tinned wire.

A real-world endorsement of Casey’s advice can be found in the harnesses of several excellent boatbuilders. For the past several years, 100% tinned wire  has been the rule at Manitou Pontoons, Crest Pontoons, and Rinker Boats. In addition, this common sense upgrade can be found on select models from Starcraft, Sunchaser and Smokercraft.

As Mr. Casey points out, this is one of those all-too-rare cases where there is a negligible upfront cost increase for using the best material available. Given the long-term benefits to boat owners of using tinned wire, one wonders why this exceptional boatbuilding practice is just that – an exception.