If you want to have a "bulletproof electrical
harness" that will last the life of the boat, this is how I wire them: Use a high quality of finely stranded, tinned, double jacketed, "marine" wire that is one size over the min. standard. Then, on the ring connectors... remove & discard the jackets, slip on 2" of adhesive
lined heat shrink, crimp the fitting, and THEN solder. Now shrink down the tubing. This seals
the entire fitting, including the end of the crimp. From here, fasten the entire wire run every 8" or so, or run it through conduit so IT CAN NOT MOVE!
It is a myth that soldering is a negative thing! This is only true in the sense of how much profit the electrician makes... OR, if one is both bad at soldering the crimps AND lets the wire flop around. If you do it correctly there is no hard spot, and a crimped ONLY wire will also fail at the crimp IF you allow it to flop around.
The proper "crimp then solder" is done with a Micro torch and the finest possible solder wire. You apply only a small drop to the far end of the crimped eye, not so much that it wicks up the wire. This creates a strong, welded, 100% sealed, wiring harness.
I have cut open crimps that I have done 15 years ago in this way, and they are still shiny and perfect!
IF one hasn't the patience for this, AT LEAST use tinned wire and crimp, then heatshrink. This is a close second.
Poorly done wiring systems, with inferior materials, are false economy! The entire system will have to be redone some day, IF it hasn't already burned the boat down.
BTW... If you buy wire by the 100' roll, it cuts the price