There are plenty of articles out there on installing new electronic gizmos and gadgets in our boat, but very few about the infrastructure those toys attach to. The fact is that many of our boats, especially the older ones, are a patchwork of wiring ill suited for new additions.

I quickly discovered that was the case on my current project boat, a 1965 Columbia 26. The wiring was old, the insulation brittle and frayed and there were a host of wires – all red and black – that I found both connected and disconnected. After looking at the mess, I decided that it would be both easier and less exasperating to remove all the old and questionable wiring, as well as the electrical panels, and start from scratch.

While you may not want to be as drastic when it comes to your own boat, there is much to recommend taking stock of your boat's electrical system and making diagrams of what exists. The exercise will help you get better acquainted with the boat, identify weak points in the system and help plan for upgrades. The diagrams themselves can also add value to the boat, by increasing the onboard documentation.

By going through this exercise and drawing these diagrams yourself, you'll be much better prepared to track down problems if something goes wrong. You'll also be aware of your system's shortcomings, and you can fix them yourself or hire a licensed marine electrician to do the job. And, of course, the next time you add gizmos and gadgets, installation will be far simpler.

There is only one caveat here: Be very careful around your boat's electrical system. Getting a sense of your boat's wiring will require some crawling around. Disconnect your boat's shore power cable and turn everything off at the breaker panel. Do your crawling in daytime and use a flashlight. Electrical shocks can be fatal, so take all the necessary precautions.

'FUNCTIONAL DIAGRAM'

I like to start with what I call a "functional diagram." To create the diagram, sketch out a rough approximation of the boat on a piece of graph paper, noting the location of major interior items like bulkheads, berths, settees and the navigation station. Then, plot the location of outlets, electrical panels, lights, batteries, instruments, fans and any other DC appliances.

Creating the diagram familiarizes you with the boat's systems and gives you a chance to consider wiring options and locations. For example: Instead of stringing several sets of smaller wires to v-berth lights, fans and outlets, you might consider running one set of heavy conductors to power bus bars, which would in turn feed those separate electrical items.

A functional diagram will help you visualize just how many wires you need and where they are going to run. Is there an accessible path or will you have to drill holes? Is a wiring chase or conduit a possibility?

Alter the diagram until the basic wiring runs and your boat's complement of electrical items are established. If you use a book or binder, you can track successive versions of the drawing and make close-up diagrams of particularly busy areas

You'll use this diagram to estimate the length of the circuits and the size of the wire you will need, so be as realistic as you can be. When in doubt, estimate a longer run.

PAUL ESTERLE