Lots of EU boats cruise the US. If you have a complex AC system you might consider keeping the boat at 220 VAC (presumably 50 Hz). You can get a step-up transformer if your battery charger won't take 120 VAC in. The downside is that A/C systems and other rotating equipment may not take kindly to 60 Hz even at the correct voltage.
For minor appliances you can install a small 120 VAC / 60 Hz inverter.
Do check the wire sizes - some EU builders pull wire sized for 120 VAC so all boats can be sold anywhere in the world when they come off the line.
Read European Power Onboard
and consider the implications heading in the other direction. *grin*