^ That will work and is cheap.
I wanted something a little more protective so I found some clear vinyl tubing, pulled the wire through it with a fish tape (you may need to lubricate the wire a little to get it to go through the tubing smoothly), and then pulled the tubing/wire combination from the front to the back of the boat using the same fish tape. Maybe a little more expensive, but water proof and may offer a little more protection. You can buy the clear tubing at Lowes.