Marine Grade Wire (and why it's important)
Marine grade wire has many more strands than automotove or industrial
stranded wire. When I counted, the automotive 14 gauge wire had 17
strands, and the marine grade wire had something like 35 or 40, I lost
count. This is important because more strands means the wire is more
flexible, which means that it will have less effect on the steering of
the bike. Yea, I realize that I'm probably just making a fuss about
very little, but since this is extra wire you'd be adding, and quite a
lot of it (3 14 gauge wires and 2 18 gauge) it can make a difference.
Marine grade wire is a lot more resistiant to failure from bending and
vibration. Considering that motorcycles are pretty vibration prone places
and that the headlight moves back and forth with the steering, these
two features are worth the money.
Also, Marine grade wire seems to be (according to the manufacturer)
larger gauge/higher capacity for the same nominal gauge than automotive
wire.