Repair & maintenance guides

How to Replace Boat Battery Cables the Right Way

Swap corroded, cracked or undersized battery cables for tinned marine cable sized from a chart for its real length and load, with crimped lugs, adhesive heat shrink, terminal boots, solid support and a fuse close to the battery.

How to Replace Marine Speakers (Including Tower Speakers)

Pick replacement speakers that fit the cutout, match your stereo or amplifier's power and impedance, survive sun and spray, and don't throw off your compass. Then wire them with the right polarity and seal them so water can't reach the back.

How to Run New Wires Through a Boat (Chase Tubes, Pull Lines and Deck Penetrations)

Get a new transducer cable, light or power wire from the stern to the helm or up through the deck without a fight: use the chase tube and a fish tape or pull string, protect the wire from chafe and heat, support it every 18 inches, seal every penetration and label both ends.

How to Size a House Battery Bank: Load List, Usable Capacity and Charging

Work out how many amp-hours your boat really uses in a day, how much of a battery's rated capacity you can actually use with lead-acid, AGM or lithium, how much reserve to add, and how your charging sources change the answer, so you buy the right house bank the first time.

How to Test and Fix Your Boat's Navigation Lights

Learn which navigation lights your boat must show and when, then test them and fix the usual culprits such as corroded sockets, loose pole-light plugs and blown bulbs. Working lights are legally required at night and in poor visibility and are how other boats see which way you are heading.

How to Upgrade Your Boat's Lighting to LED (and Keep Your Nav Lights Legal)

Switch cabin, cockpit and courtesy lights to LED to cut battery drain and bulb changes, choose navigation lights that are actually USCG-certified (not just LED bulbs), check voltage range and dimmers, seal every connection, and run the Coast Guard's simple VHF test to make sure the new lights aren't deafening your radio or AIS.

How to Wire a 12, 24 or 36-Volt Trolling Motor and Charge Its Batteries

Set up the battery bank for your electric trolling motor the right way: matched deep-cycle batteries in series or parallel, a circuit breaker sized from the motor maker's chart, a proper plug, and a multi-bank charger that keeps every battery healthy. High-current wiring that runs long distances or ties into other systems is a job for a marine electrician.

How to Wire a Bilge Pump Correctly (Automatic Float, Panel Switch and Fuse)

Wire your bilge pump so the automatic float works even with the battery switch off, the helm switch gives you a manual override, and every circuit has the right fuse, wire size and connections kept above the bilge water. A pump that is wired wrong can leave the boat unprotected exactly when nobody is aboard.

How to Wire a Marine Stereo, Speakers and Amplifier Safely

Install or fix a boat stereo the way that keeps it working and keeps your battery alive: marine-rated gear, a fused feed from the panel, a solid ground, a plan for the always-on memory wire, UV-proof speakers, and an amplifier fused right at the battery. Plus how to stop the stereo from messing with your VHF and compass.

Isolation Transformer vs. Galvanic Isolator: Which Does Your Boat Need?

Understand how a galvanic isolator and an isolation transformer each protect a boat on shore power, when the heavier, pricier transformer is worth it (stray-current marinas, aluminum boats, liveaboards), and what to ask the ABYC-certified electrician who installs it.

Low-Voltage Disconnects: Keep the Stereo and Fridge from Killing Your Battery

A low-voltage disconnect (LVD) automatically cuts non-essential loads like the stereo, fridge and cabin lights before they drain the battery you need to start the engine. Learn how these devices work, which loads belong behind one and which never do, how to pick the cut-off point for lead-acid or lithium, and how to install one safely.

Make Your Own Boat Wiring Diagram

Trace your boat's 12-volt circuits one wire at a time, label them so the labels last, and draw a simple diagram you keep aboard. It takes a few weekends, but it turns every future electrical problem or upgrade into a faster, cheaper job.

Marine Battery Care: Test, Charge and Store for Winter

Check your boat battery's health, charge it the right way for its type (flooded, AGM or lithium), and store it so it is ready in spring. Most "boat won't start" calls start with a neglected battery.

NMEA 2000 Network Basics and Troubleshooting (Plus Chartplotter Updates)

Understand the backbone, terminators, power tap and drop cables that tie your chartplotter, engine data, GPS, depth and autopilot together, then track down why a device keeps dropping off. Finish by updating chartplotter and device software the safe way.

Powering a Big Boat Sound System: Amplifier Draw, an Audio Battery and Charging

Work out how much current your amplifiers really pull, size a dedicated audio battery, keep it charged with an automatic charging relay or isolator, and fuse and wire it so a long day of music never leaves you unable to start the engine.

Recreational Radar Care: Radome and Open-Array Cleaning, Mounts, Cables and Alignment

Keep your boat's radar seeing small targets by cleaning the radome or open array the right way, checking the mount, cable and connectors for corrosion, and confirming that targets line up with the bow. Includes the safety rules for working near a radar that might transmit, plus winter care.

Remote Boat Monitoring: Bilge, Battery, Shore Power and GPS Alerts on Your Phone

Choose, install and set up a system that texts you when your unattended boat is taking on water, losing battery or shore power, or moving without you. Covers cellular versus satellite, what each sensor really tells you, wiring it so it stays on, sensible alert settings and what happens to your location data.

Satellite Internet on Your Boat: Starlink Plans, Mounting, Power and Wiring

An owner's guide to putting Starlink aboard: which plans allow coastal, offshore and in-motion use (as of October 2026), how much battery it eats, 12-volt versus inverter power, where to mount the dish, and how to route and seal the cable without leaks.

Shore Power Cord Ends: How to Judge a Cord, and When to Replace the Plug or the Whole Cord

Burned blades, a hot plug or a cracked locking ring don't always mean a brand-new cord, but sometimes they do. Learn how to inspect a shore power cord and its ends, decide between a replacement end and a new cord, what a proper sealed marine connector looks like, which parts of the job are safe for an owner and when the work belongs to an ABYC-certified electrician, plus the habits that make cord ends last.

Shore Power Inlet and Cord Upgrades: Burned Plugs, Better Connectors and Safe Adapters

Why shore power plugs and boat inlets overheat and burn, how to spot an inlet that needs replacing, what newer connector designs offer, and how to choose, size and care for cords and adapters. You inspect and buy the right cord; an ABYC-certified marine electrician replaces the inlet and its wiring.

Shore Power Safety: Cords, Inlets, Burned Plugs and Electric Shock Drowning

An owner's inspection routine for your shore power cord, plugs, boat inlet, galvanic isolator and ground-fault protection, plus the right way to plug in and the facts about Electric Shock Drowning. This guide is for looking and testing only; any electrical repair belongs to an ABYC-certified marine electrician.

Switching to Lithium (LiFePO4) Boat Batteries: What Changes and When It's Worth It

What really changes when you swap lead-acid for lithium iron phosphate (LiFePO4) batteries on a boat: the battery management system, charger settings, protecting the alternator with a DC-DC charger, not mixing chemistries, cold-weather charging, and which jobs (trolling, house, starting) suit lithium. House-bank conversions should be designed and installed by a qualified marine electrician.

Underwater LED Lights: Care, Leaks, Corrosion, Wiring and the Rules

Keep underwater LED lights bright and your hull dry. Learn the difference between through-hull and surface-mount lights, how to clean growth off the lens without damaging it, what to check for leaks, wiring, fusing and bonding, when the boat has to be hauled, and why the lights should not be on while you're underway.