Navigating the complex world of marine electrical systems can be challenging, especially when ensuring safety and protecting your vessel from potential electrical hazards. Two critical components designed to enhance security on board are marine isolation transformers and galvanic isolation.

Continue reading to learn the differences between these technologies.

Do You Need an Isolation Transformer on Your Boat?

While you don’t require an isolation transformer on all boats, it can be helpful for several reasons. To begin with, it can keep you and your passengers safe from electrical shock. Suppose there is an electrical fault in the shore power supply. In that case, an isolation transformer will prevent that fault from being transmitted to your boat’s electrical system, reducing the risk of electrocution.

Furthermore, an isolation transformer can protect your boat’s electrical equipment from galvanic corrosion damage. By separating your boat’s electrical system from the shore power supply, an isolation transformer can prevent this type of corrosion.

Key Differences

The primary difference between marine isolation transformers and galvanic isolators is their intended purpose. Marine isolation transformers provide electrical and galvanic isolation from the shore power supply, offering additional benefits such as voltage regulation and enhanced safety. Galvanic isolators, on the other hand, are specifically designed to prevent galvanic corrosion but do not provide electrical isolation.

Marine Isolation Transformers

Marine isolation transformers can help with the following:

Electrical Isolation

The core purpose of a marine isolation transformer is to create an electrical barrier between the boat’s electrical system and the shore power source. This barrier effectively blocks the transmission of electrical anomalies, like voltage surges or current seepage, from the shore power to the boat. This safeguard guarantees the protection of both the vessel and its occupants.

Voltage Regulation

Marine isolation transformers also regulate voltage, stabilizing the voltage supplied to the boat. This is crucial because voltage fluctuations can damage sensitive electronic equipment on board.

Galvanic Isolation

In addition to electrical isolation, marine isolation transformers offer galvanic isolation, which protects against galvanic corrosion. This is especially important for boats in saltwater environments, as it prevents the flow of stray currents that can corrode the boat’s metal components.

Improved Safety

By preventing electrical faults and offering galvanic isolation, marine isolation transformers enhance the safety of the boat’s electrical system and reduce the risk of fire or electrocution.

Galvanic Isolators

Galvanic corrosion is a common issue on boats and yachts. Galvanic corrosion occurs when two metals with different properties come into contact with an electrolyte, such as seawater. This interaction can result in the increased corrosion of metal elements on the boat, including the hull, propellers, and through-hull fittings.

Here are some key features and benefits of galvanic isolators:

Galvanic Corrosion Prevention

Galvanic isolators break the electrical connection between the metal components of the boat and the shore power ground. You can achieve this by inserting a diode bridge in the boat’s grounding conductor.

Cost-Effective Solution

Galvanic isolators are a cost-effective solution for addressing galvanic corrosion issues. They are relatively easy to install and provide protection against corrosion.


Many marinas and boatyards require galvanic isolators as part of their electrical safety regulations to prevent galvanic corrosion from affecting multiple boats near each other.

Ready to confidently navigate the seas and protect your vessel from electrical risks? Discover the essential disparities between marine and galvanic isolation transformers with Bridgeport Magnetics Group, Inc. Make informed choices to fortify your marine electrical systems, ensuring a safe and worry-free voyage. Contact us at (203) 954-0050 or for more details.