Just bought a boat today and the last person that had it wasn't to good at wiring it up and honestly it looks like a mess and is in desperate need of a complete rewiring. I'm more than likely going to try and do it myself and was wondering what's the most cost efficient way to go about and just how difficult is a complete l rewire. any help will be greatly appreciated. thanks 

What are you rewiring? Fishfinders, trolling motor, fuse box, everything? 

For the fuse box/dash, the most cost efficient is to buy a new fuse box and wiring kit, unless you happen to have 20 different colors of wire on hand! 

For the fish finders, just run new 12 ga wire to your new fuse box and dedicate a spot for them. 

For the trolling motor, use 8ga and wire it up with new breakers. 

Be sure to use marine grade wire for everything! 

for right it everything but the fish finder that is going to be rewired