ABYC Marine Corrosion Certification Practice Exam 2025 - Free Marine Corrosion Practice Questions and Study Guide

A galvanic isolator is designed to prevent galvanic corrosion in marine environments by blocking DC currents while allowing safe AC currents to pass through. Its primary function is to create an effective barrier between the boat’s electrical system and shore power, which tackles the issue of galvanic corrosion caused by stray DC currents.

The statement that a galvanic isolator will block stray AC is false because its design and purpose do not include the blocking of AC. In fact, a galvanic isolator must allow AC to pass in order for the electrical systems aboard to function normally and to ensure that devices reliant on AC power can operate as intended. Therefore, since a galvanic isolator does not block AC, the correct response aligns with the understanding that it blocks DC currents while permitting AC flow. This distinction is crucial for maintaining the balance between protection from corrosion and the functionality of electrical systems on a vessel.