Shore power is the backbone of the yacht electrical system while docked. It allows charging batteries, running HVAC, and powering all onboard electrical devices. Having a reliable, well-designed, and properly maintained shore power system makes all the difference, and it is very important to ensure safety and reduce fire hazards.
At OSA Solutions, we specialize in the design, troubleshooting, and optimization of yacht shore power systems — from power inlet to panel.
What Is Shore Power?
Shore power allows your yacht to draw electricity directly from the dock when you’re moored, powering onboard systems without running the generator. It’s a critical part of modern yacht operation — especially when you’re docked for extended periods and want quiet, clean, and reliable power.
In the United States, there are several common shore power configurations found at marinas, depending on the size of the vessel and marina infrastructure:
- 125V – 30A — Common for small boats. Limited power, usually supporting basic onboard systems.
- 125V / 250V – 50A Single Phase — The most widely used system for mid-size yachts. Typically supports larger appliances, air conditioning, and entertainment systems.
- 125V / 250V – 100A Single Phase — Found on larger yachts requiring greater capacity. Offers more headroom for high-demand equipment.
- 208V – 100A Three Phase — Seen in commercial docks or high-end marinas. Offers smoother, more efficient power for large systems.
- 480V – 100A Three Phase — Used by superyachts or in commercial marine settings. High power delivery for complex vessels with large onboard systems.
Not all yachts are designed to accept these shore power types natively. Many vessels — especially those built in Europe — are equipped for 230V 50Hz electrical systems. When these yachts arrive in the U.S., they encounter dockside power supplies that deliver 120/240V at 60Hz, which are fundamentally incompatible.
A European yacht cannot be safely connected to American shore power without a proper power conversion system.
Attempting to connect directly can damage onboard equipment, create electrical hazards, or violate marina safety regulations. This is where power converters and isolation transformers become essential — they adapt voltage, frequency, and phase to safely match U.S. shore power standards.
At OSA Solutions, we specialize in converting imported yachts for use in American waters. Our custom shore power solutions ensure full compatibility, protect your onboard systems, and keep you compliant with marina and ABYC standards.
Shore Power Converters
In addition to frequency adjustment, these converters also manage voltage transformation and phase alignment, allowing vessels to connect safely to a wide range of shore power sources across different countries and marinas.
Shore power converters are advanced onboard systems that adapt dockside electricity to match a yacht’s internal power requirements. Their most critical function is frequency conversion — changing 50Hz power to 60Hz or vice versa — which is essential for compatibility with electrical systems designed for specific regional standards.
Leading manufacturers in the industry include:
- Atlas Marine Systems – Known for high-performance converters with global compatibility
- Eekels Technology – Offers reliable, heavy-duty marine electrical solutions
- Marpower – A division of Eekels, specializing in compact, modular converter designs for marine applications
These systems are built for continuous operation, delivering stable and clean power to critical onboard systems regardless of where the yacht docks.
Isolation Transformers
Similar to power converters, isolation transformers are widely used in medium to large-size vessels. They can transform voltage levels and modify system polarization, while also providing galvanic protection when the boat is docked. This helps prevent corrosion caused by stray currents from shore power systems.
Unlike power converters, isolation transformers do not modify frequency or phase, but they do offer protection against voltage spikes and other shore power irregularities. Many models also include voltage boost capabilities, which are especially useful in marinas where low voltage is a common issue.
At OSA Solutions, we bring deep experience working with isolation transformers to deliver seamless installations, system servicing, and custom solutions — including automatic voltage boost control and shore power system design. We’ve also integrated isolation transformers into power conversions for foreign-built vessels, offering a more cost-effective alternative to full power converters in specific cases.
Bringing It All Together
Shore power is a critical part of any yacht’s electrical system, and getting it right means more than just plugging in. From understanding different voltage and frequency standards to choosing the right equipment like power converters and isolation transformers, every detail matters.
Whether you’re docking locally or traveling internationally, a safe, reliable shore power system ensures your vessel operates smoothly and stays protected. At OSA Solutions, we understand the technical challenges behind these systems and deliver solutions built for performance, safety, and long-term reliability.