So I am in the process of rewiring the boat, I have a Holley Blue marine fuel pump that is currently connected directly to the battery, is there any reason not to run a fuse to this? and if so what size?

Thanks
Bryan

Protect yourself with a fuse ! It has an electric motor. Holley should able to provide you with an Amperage chart.

Breaker.

Always fuse. Fuses aren't there to protect the device. They are there to protect the wire going to the device in case of a short, thus why you always see the 'fuse within 7" of battery'

Thanks everyone for confirming what I thought should be right in the first place. When I saw how they wired everything I started to question.... But now will continue with the way it should be wired
Thanks again

breaker then relay for the power...

30amp relay at the minimum

Absolutely and an oil pressure switch to trigger the relay.