The galvanic isolator prevents electrolytic corrosion. It blocks low voltage DC currents that enter your boat via the shore power earth wire. These currents can cause corrosion to the boat's underwater metals, like the hull, propeller, shaft and so on.

The Isolation Transformer eliminates any electrical continuity between AC shore power and the boat. It is
essential for safety and eliminates the need for galvanic isolators and polarity alarms.