ESSENTIAL BOAT ELECTRICS,
God help anyone who has to wire his own boat but, if you are the capable sort who understands these things, this looks like a decent guide, crammed with circuit diagrams, tools needed and tables of numbers of things. It starts o so cheerfully! The only things we need to know, we learn, are: fuse size, how much power a thing uses, wire thickness, and how long you can run a thing o the battery. Then it gets deeper… and deeper… and deeper.