Couple of things, I hold a USCG Unlimited Chief Engineers License so this was a big part of earlier life. First the type of wire you run should be Tinned DC wire, lots of little strands to prevent Counter EMF. Stranded AC wire or Automotive grade will have a higher resistance to electron flow. Second is the terminals used, you want Silver plated Copper only. To further reduce voltage drop after crimping solder them. Adhesive lined Shrink Tubing applied to a bare soldered terminal is a Top Shelf way to terminate. Back to front like you are running 10 gauge wire is the minimum size I ran for electronics on these 24ft Bay Boats when in my shop for a T-Top. I run a single pair then install sub-distribution equipment in the bow. Blue Sea Systems fuse bus with ground distribution is all I use they come with a clear Cover/Guard. Sum of the voltage drops equals source voltage, wire quality & size - termination quality - and in some cases Induction can lead in good direction or bad. You don't want your supply wire to run next to the trolling motor supply wire due to Induction. Anytime I have had to run supply lines next to DC Motor supply lines shielding over the wire must be used.
