In our daily lives when we have a problem we solve it in the most efficient and cost effective way possible. When presented with more than one option to solve an electrical problem for a marine application we will instinctively choose the least expensive one not taking into account or ignoring the fact that this decision may alter and even endanger our boats.
From the outside the differences between cables is only noticeable by the colour or feel of the insulation but this does not tell the whole story. There are many important differences between a marine electrical cable and the cables that are used in the residential and construction industry.
When compared, the residential against the marine cable the residential has only one solid strand of cable. Once this cable is placed and secured inside the walls and ceilings there are very few factors that will cause it to shift from its place, thus friction and flexibility are not an issue. On the other hand marine cables have multiple strands of very fine hairs of copper that give the cable its necessary flexibility to sustain the vibrations that are a constant factor in the marine environment. Every one of the hairs of copper within a marine cable is coated individually with tin to delay or even prevent corrosion.
Another factor of distinction between the two applications is that the possibility of the residential cable being in contact with corroding chemicals is almost non-existent. The marine cables that are used in boats need to sustain chemical exposure like diesel fuel for instance. Marine grade wiring has wiring jackets that are quite specialized and resistant. The temperature rating of marine cables is another advantage. It's important for marine cables to be able to withstand the temperature found in an engine room without affecting the performance of the cable.