What device provides electrical isolation and voltage conversion between the shore outlet and the boat's electrical system?

The device that provides electrical isolation and voltage conversion between the shore outlet and the boat's electrical system is a transformer.

A transformer operates using electromagnetic induction to convert alternating current (AC) voltages from one level to another. It allows for safe transfer of electrical power while isolating the boat’s electrical system from the shore power supply. This isolation is crucial in marine environments to prevent electrical faults from affecting the shore power supply and to protect the boat's electrical systems from fluctuations in voltage or potential short circuits.

While an AC Shore Power Voltage Regulator and an AC Shore Power Converter might seem relevant, they do not provide electrical isolation in the same way a transformer does. Regulators typically adjust voltage levels to maintain a certain output, and converters are used to change AC to DC (or vice versa) but may not address isolation and voltage transformation in the same manner. A rectifier, on the other hand, converts AC to DC, which is not the primary function related to the isolation and conversion from shore power to a vessel's system.