How is a boat's hull potential typically measured?

The measurement of a boat's hull potential is typically performed by assessing the voltage between the hull and a reference electrode, often referred to as a reference cell. This method is essential for evaluating the level of galvanic corrosion potential that the hull may be exposed to in the marine environment.

When the hull is compared against a standardized reference electrode (such as a copper-copper sulfate reference cell), it provides a clear indication of the potential difference, which is crucial for assessing corrosion risk. The main engine negative terminal is commonly used as a reference point, ensuring that the measurement reflects the electrical potential accurately relative to the vessel's grounding system.

Other methods, such as using a multimeter, resistance meter, or ammeter, do not capture this specific potential measurement relative to the reference cell. While multimeters can measure voltage, they do not specifically account for the galvanic environment or the reference needed for hull potential. Resistance meters focus on measuring resistance rather than potential differences, and ammeters measure current, which is unrelated to potential evaluation. Thus, the process of measuring hull potential with a reference cell provides a comprehensive understanding of the conditions surrounding the boat's electrical system and potential corrosion issues.