In the USA the two commonly supplied shore-power voltages are 120 Volts (60Hz) AC and 240 Volts (60Hz) AC. The standard in Europe is 230 Volts (50Hz) AC. All of these supplies are single phase, but there are differences in the supply wire configurations and consequently in the power distribution panel structure. The chart below illustrates the differences.
Standard European practice and ABYC requirements include ground-fault protection for the entire AC system as well as critical branch circuit GFCI protection.
Please reference: Technical Brief "AC Ground Faults, the Boater, and ABYC—Understanding Equipment Leakage Circuit Interrupters (ELCIs) and Ground Fault Circuit Interrupters (GFCIs) to make your boat safer." for more information.