Boat Electrical Systems Checklist: 18 Questions Every Boat Owner Needs to Answer

Marine Electronics Guide: 18 Questions Every Boat Owner Needs to Answer

We know how serious you are about your boat, your beauty, your dream!

She needs power to move, find her way, and keep you comfortable on board.

When it comes to the electrical system on your boat, there are a few things to check to make sure your marine electronics are safe, reliable and performing optimally. If you don't feel at ease with the electrical side of things, now’s the perfect time to start learning, or get a professional involved.

Here is an electrical system checklist that’ll help you stay on top of your boat’s power; keep your boat sailing, and your crew safe – oh, and save you money in the long run!



A lot of “faulty equipment” and electrical hazards on boats come down to the basics of wiring. If done right, you’ll be smiling, if not, you’re in for some major headaches and expense.

Be smart, take care of your wires.

1. Are Those Wires Supported?

It may sound obvious, but the wires on board need to be secured.

Vibrations, flexing, heat and movement can slowly wear your wires creating weaknesses in the insulation and eventually exposing the wire itself – this is dangerous!

Installing clamps (with padding) every 18 inches is recommended.

2. Any Signs of Chafing?

Chafing is the most common cause of electrical fires on boats!

You’ll need to inspect your wires for signs of chafing, especially in places where the wires come into contact with sharp surfaces and in areas of increased vibration (close to the engine, etc.).

Using appropriate coverings should protect your wires from chafing, such as:

  • Grommets
  • Conduit
  • Several rounds of electrical tape                                                                              

Boat Electrical Systems Checklist: 18 Questions Every Boat Owner Needs to Answer

Don’t forget to check these points often to make sure they’re holding up!

3. Are the Electronic Components Neat?

One can get a feel for the health of the electrical system by the neatness of it.

Scrappy joins, loose wires (hello spaghetti!) and a general lack of order makes the system difficult to monitor, maintain and repair. This is a common concern in pre-owned boats, and it can make any necessary repairs both frustrating and a lot more expensive.

Keep it neat, and call in a professional if you need help getting it straightened out.

4. Correct Materials Used?

Remember that boat electrics are a world apart from house electrics – seriously, it’s a totally different ball game! One of the big differences is the material used.

All the wire on board should be specified as boating cable, NOT your typical wire from your local home or DIY store! Boat Cable is copper-tinned wire with robust insulation – perfect for the marine environment (wet, temperature fluctuations and a lot of movement).

5. Healthy Connections?

Wire connections are often where trouble brews and one of the first checks to make when things go wrong.

Inspect your connections regularly – look out for any corrosion that could lead to hot spots (i.e. fire hazards) and make sure that all connections are secure (no room for play) and installed properly – never making use of tape or wire nuts!

Splices should be avoided as much as possible (they add resistance to your circuits and any extra connections or joins increase the likelihood of something going wrong), but in most cases, they will be a part of your electrical system. Make sure they are done correctly and make use of terminals instead of having a bundle of splices in your system.

 Boat Electrical Systems Checklist: 18 Questions Every Boat Owner Needs to Answer

6. Are the Wires Dry and Protected?

While your electrical system is in a boat, it is important to minimize its exposure to moisture. Water and electrics do not go well together and combining them will rapidly deteriorate your electrical system.

Keep your wires dry and keep vital equipment (batteries, generators, instruments, etc.) covered – not exposed on deck or in the bilges, unless you're ready to replace them often! Drip loops can help prevent condensation from dripping down on to connections so be sure to install these where there’s a chance that moisture will sneak in.

In the event water has seeped into areas such as your bilge, a product such as Rejuvenate Marine’s Bilge Cleaner and Degreaser will safely help eliminate odors while cleaning oil, grease and sludge.

7. Is Your System Grounded Correctly?

This is a tricky part of boat electrical systems and probably the most poorly understood (unless you’re a marine electrician).

Stray currents in the water at the marina, lightning and other factors need to be taken into consideration to protect not only your electrics but the metal composition of your hull from galvanic corrosion and electrolysis.

By using capacitors, bonding correctly and getting a professional involved (someone with experience) you’ll be able to safeguard your boat and electrics from these potentially hazardous phenomena.


Fuses and Circuit Breakers

Fuses and circuit breakers are essential parts of your electrical system; they keep your appliances, components, and electrical system safe from excess current (i.e. they prevent everything from getting fried!)

8. Correct Application?

Both fuses – which “blow” and need to be replaced – and breakers – which “break” and can be reset – offer circuit protection, so how do you know which to use?

According to Wayne Kelsoe, chief technology officer for Blue Sea Systems, fuses are best in DC applications and circuit breakers in AC systems.

9. Location, Location, Location!

Knowing whether to use fuses or breakers is important, but equally important is knowing where to install them.

Remember that the purpose of fuses and breakers is to protect your wires, by doing so they protect your entire electrical system and all your equipment.

Therefore, the best place to install breakers and fuses is as close to the power source as possible – this prevents long stretches of wire being overheated and damaged during situations of excess current.

Makes sense, right?

10. Sizes and Ratings Correct?

Ensure that the fuses that are installed are rated correctly – they all look the same so take special care to read the rating carefully and clearly label the fuse to make it easier the next time you need to replace it.

Knowing the rating of the wire is just as important as knowing the rating of the fuse. If the wire after the fuse has a lower rating than the fuse, the current will flow through the fuse and still overheat the wire –  your fuse needs to be rated lower than the wire on either side of it for it to offer the protection you need.


Ignition Protection

11. Is Your System Fireproof?

While it is best practice to route wires away from parts of the boat that may be exposed to exhaust fumes or other flammable gasses and heat, in some situations, this is simply unavoidable.

In these cases, you’ll need to ensure that those components are ignition protected (incorporate systems of seals and flame arrestors that make ignition impossible).

Boat Electrical Systems Checklist: 18 Questions Every Boat Owner Needs to Answer


Battery Considerations

At the end of the day, your batteries are the ones that supply your power and store your power – the heart of your boat. If you want to enjoy the benefits of electricity on your boat (and I'm pretty sure you do), then you need to take care of this essential component!

12. Are the Batteries Accessible?

Accessible batteries are batteries that will be maintained and inspected and will most likely last the longest. Relocate your batteries if they are currently hard to reach.

13. Are the Batteries Clean and Dry?

To get the full life out of a battery – and to keep it reliable – it needs to be kept clean and dry (especially around the terminals!). A dry, covered location is the best way to go.

14. Are the Batteries Good?

Investing in a good quality battery is wise. It can be so tempting to go the cheaper route but don't be mistaken; it'll cost you in the long run.

There’s no point in buying a great battery and then not installing it correctly – make sure that battery is perfectly connected to your system.


Map it Out

Knowing where things are and what’s what can make difficult situations much easier to deal with. This is one instance where it’s a really good idea to “check the manual.”

Boat Electrical Systems Checklist: 18 Questions Every Boat Owner Needs to Answer

15. Do You Have an Updated Schematic?

While this may sound like a luxury or something that only comes with new boats – having a schematic or even sketching one of your own will make your own life simpler and safer!


16. Is Everything Labelled Correctly?

Along with a neat system, a well-labelled system using the “conventional” colors will help you locate the correct cables with confidence and help you avoid potentially fatal mistakes! This is one of those cases where it pays to be nerdy and super organized – you'll thank yourself later.

Boat Electrical Systems Checklist: 18 Questions Every Boat Owner Needs to Answer


Be Prepared

17. What Can You Do When Something Goes Wrong?

Knowing some basic trouble-shooting will give you peace of mind when it comes to the electrical system on your boat.

Here are some key approaches.

  • Listen to your equipment – some instruments or appliances have built-in diagnostics that alert you when something is wrong, this can save you a lot of time and hassle!
  • Read the book – your owner’s manual is filled with helpful trouble-shooting advice for common issues. If you don’t have one for your boat, you’ll most likely be able to download one.
  • Reset equipment – you may lose some "history," but it can clear any processing glitches that might be causing trouble.
  • Pull the plug – as a last resort you may have to reset the system via the circuit breaker. Avoid doing this often as you can damage the breaker; remember to wait a while before turning on the power and to start up appliances slowly.

18. What Will You Need When Something Goes Wrong?

Stuff happens.

There are certain things you need to keep handy if something goes wrong in your electrical system, especially if you're out in the middle of the ocean.


  • Spare boat cable
  • Spare fuses (keep a list of the different ones on board)
  • Terminal lug kit
  • Electrical tape
  • Testing instruments (volt-ohm meter)
  • Hand tools (including a crimping tool)
  • A water-tight sealant and an anti-corrosive spray


Now that you have a basic idea of the various components of your electrical system, spend some time looking closely, building up your understanding, and making changes that’ll keep your boat going for years to come.


You’ll enjoy boating so much more in a vessel that is reliable, functional and well-cared for. Choose a good stainless steel cleaner and polish to restore all chrome and stainless surfaces on your boat to a brilliant shine.


Happy boating!