Discussed millions of times on here. A look through the
archives will be enlightening.
There are a number of different ways to deal with this, depending the exact
equipment you have on board. If you are willing to get rid of or not use or put on a separate inverterted circuit any
equipment which is really sensitive to the frequency, then you can simply transform the voltage at the source, using for example a
Victron isolation transformer, and Bob's your uncle.
OR, if you want the whole boat to have pure, perfect 110v/60hz
power, you can produce that with an
inverter or gang of them. Feed the
batteries with a separate dual voltage
battery charger. And once again Robert is your uncle.
I have a boat with a whole lot of AC
electrical equipment on board, and the second thing is what I would do. I have a
Victron inverter/charger, through which my normal 230v/50hz
shore power, as well as
generator power, runs. If I were venturing to 110v/60hz land, I would simply add a Victron Orion battery
charger with its own
shore power inlet for 110/60. And that would suit me fine. For any periods where I need more power than the inverter will produce, I would just run my 6.5kW
generator.
That's kind of a thumbnail; in the
archives you will find much more detailed and technical discussion.