If you are not running an emmersion heater or something else with a high Watt load, the wiring will be OK. In any case, its only the wire running up to the transformer that takes the 110V 2x Amps load. Beyond it, the voltage is 220 V and current normal for a 220V wired boat.
Most things will be running on the DC circuits, which are the things that are intended to run offshore, so its only the direct AC loads are a worry. Check the battery charger is not worried by 60 Hz. If the boat can drive its 220V installations through an inverter from the batteries, then the charger may be the only item sensitive to 60Hz.