wrote:

I want to install my battery in the bow of my 16 foot skiff. The
battery will power the starter for a 25 horse electric start
evinrude.
The total cable length will be 18 feet, no breaks. What guage wire
do
I need to use, do I need to use something as big as a car like 4
guage, or can I use 8?? How many amps does a typical 25 horse draw?

If you are looking for conformation that you can do the job on the
cheap by using small wire, look elsewhere.

#2AWG will do the job correctly.

Lew