There are a few things you should know about marine electrical systems. At the simplest level, they are very different even when they look like devices in your house. Ask before plugging something in.
The next-level of understanding marine electrical systems centers around verifying that voltages AND frequencies (50 or 60 Hz or cycles/second) are compatible with your device. This is especially important on a Liveaboard that caters to passengers from around the world. You not only risk burning up your device, but you could start a fire offshore where there’s no fire department to call.
There is another harder to understand aspect that is especially complicated by devices made for the North American Market: Grounding and Bonding. Every building with its own electrical service has one or more ground rods driven into the earth. This helps prevent people from being electrocuted. There’s no place to drive a ground rod on a ship or boat. Using the vessels’ hull to carry current to ground via sea water creates huge problems with electrolysis and can burn out other electrical devices onboard.
Understanding this is really important for small boat owners that are large enough for a generator. Installing the wrong device can cause huge problems on your hull and everyone else’s in the marina. Anodes can corrode 10x faster, bronze hull fittings can crumble, and you won’t be very popular with the owner of that Aluminum boat tied up next to you.
Above all, don’t use a landlubber electrician!
Marine electrical systems are quite different, especially in North America. There is no Neutral that is tied to ground at the panel and expen$ive generators can get damaged when incorrectly interfaced to shore power. Don’t use less expensive automotive battery chargers or many other grounded devices made for use onshore. Check first and get a marine electrician when you aren’t positive. You can’t trust the advice from your local hardware store.