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Greece may enjoy mild winters compared to Northern Europe, but coastal humidity, salt air, and months of inactivity can still cause serious damage to your yacht’s electrical systems. Proper winterization prevents corroded connections, dead batteries, and expensive spring repair bills. This checklist covers every electrical step you need before leaving your yacht for the winter season.
Why Electrical Winterization Matters in Greece
Even in the Mediterranean, winter brings increased humidity, rain, and temperature swings between day and night. Condensation forms inside junction boxes, behind electrical panels, and around battery terminals. Left unchecked, this moisture accelerates corrosion on every exposed connection and can cause short circuits when you recommission in spring.
Yacht owners who skip electrical winterization routinely face common marine electrical problems that could have been prevented with a few hours of preparation. The investment in proper shutdown procedures saves far more than it costs every single season.
Battery Storage and Maintenance
Batteries are the most vulnerable component during winter layup. A fully charged battery resists freezing and sulfation, while a discharged battery deteriorates rapidly. Before shutdown, charge all batteries to 100 percent and clean the terminals thoroughly with a baking soda solution.
For lead-acid and AGM batteries, either remove them to a dry, temperature-stable location or leave them aboard with a quality marine float charger connected to shore power. Victron IP22 or CTEK Marine chargers are excellent choices for winter maintenance charging.
Lithium LiFePO4 batteries should be stored at 50 to 60 percent state of charge if disconnected. Their built-in BMS will protect against deep discharge, but they should never be charged below 5 degrees Celsius. Our guide to lithium vs lead-acid marine batteries covers these differences in detail.
Regardless of battery type, disconnect the main battery switches to prevent parasitic drain from electronics in standby mode. Even small loads like bilge pump float switches or alarm systems can flatten batteries over several months.
Shore Power During Winter Layup
If your yacht remains connected to shore power during winter, inspect the shore power cable, inlet, and all connections before the season ends. Look for any signs of heat damage, discolouration, or corrosion on the plug pins. A faulty shore power connection left unattended for months creates a fire risk.
Install a dehumidifier below decks to control moisture if shore power is available. Make sure the dehumidifier is connected to a dedicated circuit and that the drain is routed overboard or into a collection tank. Review our shore power safety guide to ensure your setup meets all safety requirements.
If you disconnect from shore power entirely, make sure all AC circuit breakers are switched off at the main panel. This prevents any possibility of accidental energisation and reduces the risk of electrical faults while the yacht is unattended.
Protecting Navigation Electronics
Remove all portable electronics including handheld VHF radios, tablets, and removable chartplotters. Store them in a dry, secure location at home. For fixed electronics like radar domes, multifunction displays, and navigation instruments, cover them with protective covers to shield against UV and rain.
Disconnect antenna cables from AIS and VHF units and cap the connectors with protective covers or wrap them in self-amalgamating tape. Moisture inside coaxial connectors causes signal loss and corrosion that is expensive to repair.
If your yacht has a NMEA 2000 network, there is no need to disconnect individual sensors, but powering down the network by switching off its dedicated breaker is good practice. This eliminates standby power consumption and reduces wear on network components.
Corrosion Prevention Checklist
Apply a thin layer of dielectric grease or CRC Marine Corrosion Inhibitor to all exposed electrical connections, battery terminals, and shore power contacts. This creates a moisture barrier that dramatically slows corrosion.
Inspect all zinc anodes and replace any that are more than 50 percent depleted. Anodes protect against galvanic corrosion when your yacht is connected to shore power alongside other boats. Without adequate anodes, stray currents can eat through underwater fittings during winter. A professional marine electrician can test for stray current issues before you leave your yacht for the season.
Check all cable glands, deck penetrations, and junction boxes for signs of water ingress. Seal any gaps with marine-grade sealant. Even a small amount of water in a junction box will cause significant corrosion over a Greek winter.
Preparing for Spring Recommissioning
Create a written record of everything you disconnected, switched off, and treated during winterization. This makes spring recommissioning much faster and ensures nothing is forgotten. Include battery voltage readings taken at shutdown so you can compare them in spring.
Schedule a professional electrical maintenance inspection for early spring, before your first sail. A qualified marine electrician can identify any winter damage, test all circuits, and ensure your yacht is safe and ready for the season.
At A Yacht Marine Services, we offer comprehensive winterization and recommissioning services for yachts across Athens, Piraeus, and the Greek islands. Contact us to schedule your end-of-season electrical inspection.
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