Correct fuse size

[Ralph Wiggum]

I am going to install a fuse panel in my boat to get rid of the tangle of wires/terminals that go to the battery.

How do I select the correct fuse rating for each component (12v outlets, nav lights, bilge, livewell, sonar, radio, etc)?

[JohnMickish]

What size wire did you run to the stuff? What is each item rated for? If you have something that uses 5 amps you won't need a 20 amp fuse and at the same time it won't run on a 3 amp fuse either. As a rule of thumb, I'd start with 10 amp fuses and see what holds and what dosen't. In no case should you need anything over 20 amps.