What characteristic feature is essential for galvanic isolators in preventing electrical hazards?

Galvanic isolators are designed to prevent galvanic corrosion by blocking direct current (DC) while allowing alternating current (AC) to flow. The critical function of current blocking is essential because it isolates the grounding of the vessel’s electrical system from the shore power source, which helps prevent the flow of unwanted currents that can lead to electrolysis and corrosion of metal components in the water. This characteristic not only protects the integrity of the vessel's metal parts but also enhances overall safety by minimizing the risks of electrical shocks to individuals in contact with the water.

High efficiency, current limiting, and overvoltage protection, while they may be relevant in other contexts, do not specifically address the primary function of galvanic isolators, which is to prevent harmful DC currents from creating corrosion and unsafe conditions. Thus, the proper selection and functioning of current blocking within galvanic isolators are vital in maintaining marine electrical safety.