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Learn boat wiring from the experts

Our review of Boat Electrics 101, a new online course, co-developed by marine electrics expert, Nigel Calder.

When we bought our 1970s-era sailboat, the boat wiring was a disaster.

We soon discovered a rainbow spaghetti mess of unlabeled electrical wires behind our DC electrical panel. Legacy marine electrical systems from a previous “rewiring” made trouble-shooting and tracing wiring runs exasperating. Lights and pumps regularly failed and we once lost power entirely (despite being on shore power).

In short, living on a poorly wired boat was a nightmare. We needed to learn about our boat’s electrical if we were ever going to go bluewater cruising.

boat wiring
Getting to terms with our DC panel wiring

A quick note that this post contains affiliate links (so if you purchase through a link we’ll earn a small commission). We received free access to this course in exchange for a fair and honest review. All the opinions are our own.

Learning how to wire a boat

The good news is that while boat electrical may seem intimidating, it’s actually not all that difficult to get the hang of—but it does have to be done right!

The challenging part was finding a good teacher. We hired an electrician we found on Craigslist to show us the ropes, but this proved to be a complete disaster (with him shorting out the dock mains at our marina and frying our inverter).

After that experience, we resolved to teach ourselves, sorting through the good, bad, (and sometimes, downright dangerous) boat electrical advice available online.

Fortunately, there is now a FAR better way to learn boat wiring…

Photo credit:

Boat Electrics 101

Boat Electrics 101 is the online course I desperately wish we’d had at the time. It launched in 2021 and was created by arguably the world’s smartest people on marine electrics including boat systems guru, Nigel Calder.

If you’re not familiar with Nigel, you’ll find his mechanical and electric books in just bout every bluewater cruiser’s library. These guys really know what they’re talking about!

Boat Electrics 101 is the brain child of marine experts Nigel Calder, Dr. Jan C. Athenstädt, and Michael Herrmann. Photo credit:

In the course you’ll learn:

  1. The basics of how electricity works
  2. Electrical system components and how to safely connect them
  3. How batteries work (and what you can do to double or triple their lifetime)
  4. Energy system design: how to balance your energy storage, consumption, and generation
  5. How to plan a (re)wiring of your boat (including making your own boat wiring diagram)

Unlike my grade 10 science teacher, the course does a great job of taking an important concept and breaking it down with animations, diagrams, and videos.

For example, In one module, Calder demonstrates the importance of circuit breakers by driving a screw through an unprotected wire. The cable immediately went up in flames, filling the room with smoke! Lesson learned.

Sample graphic from Boat Electris 101. Photo credit:

Best of all, all of their materials follow ABYC and ISO standards. Both Nigel and Michael have been members of American Boat and Yacht Council (ABYC) and the International Organization for Standardization (ISO) committees, so they know the rules and best practices better than anyone.

I’ve taken Boat Electrics 101 and can’t say enough good things about it. If you sign up now, you can take advantage of their early bird offer ($199) and save $100. Oh, and you keep your access to the course forever (even as they add new material). Even if it saves you hiring a marine electrician just once, the course more than pays for itself.

The rewards of doing it yourself

Learning how to wire a boat was not only rewarding but it made us more capable, self-sufficient boat owners. It’s an essential skill for people with older boats, but even new boat owners will find there comes a day when an electrical component fails or they want to add more bells and whistles.

We’ve saved a lot of money by doing our own marine electrical work (not to mention avoided days stuck in port waiting for a professional marine electrician). So, don’t let marine wiring intimidate you. With the right knowledge and tools, you’ll be well on your way to doing your own marine electrical.


Sunday 23rd of January 2022

I learned the hard way about boat electrics when locked onto the engine block and a battery charger on a sailboat connected to shore power with a faulty ground. I was being tazered by 240v.

My friend saved my life by pushing me off the engine with a broom handle!

Yes, understanding boat electrics is something that is as important as navigation!


Sunday 23rd of January 2022

Oh my gosh, that sounds terrifying! What a nightmare. I'm glad you're okay. That was some good quick thinking on your friend's part!

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