Once you leave the Virgins you are leaving the 60 hertz, North American 220 shore power. Beware. Sometimes you will find what look like North American plugs. But they may not provide North American power. You need a multi-meter and the ability to determine hertz.
St. Lucia's Rodney Bay has a couple of docks which are North American 220 and 60 hertz, but even there the majority of slips are European 220 and 50 hertz.
Note, the 50 hertz is the problem. Some appliances will not work with 50 hertz. Thus for those marinas that provide a step-down transformer you will still have to deal with the 50 hertz.
If you are just doing a tour of the Eastern Caribbean I suggest you find a battery charger that accepts European 220 v and 50 hertz. Use this to charge your batteries and then use your inverter to power the boat. This is called the poor man's isolation transformer. Many of us from North American have two separate inverter / chargers and thus use one to charge and the other to invert. Note, the inverter/charger connected to the European shore power must be set to charge only, otherwise it may pass through the 50 hertz 220 power.
Many of the trawlers staying in the eastern Caribbean have isolation transformers, expensive. These will convert European 220 to North American 220, but they do not change the hertz. We along with most others have bought appliances which can accept 50 hertz.
Because we have an isolation transformer we can connect our shore power outlet to the European 220. But our washing machine requires 60 hertz so we still use the two inverter/chargers.
We also have installed a separate shore power inlet, 30 amps, to connect directly to the European 220. This powers only two duplex outlets on the boat. We use this when we store the boat for the summer. It runs a dehumidifier and has the ability to run a small 20 amp charger. Reason for the separate shore power inlet is that it is fool proof, and by that I mean I don't trust the boat yard guys to deal with European power coming into the central panel. One mistake and they can blow up the appliances.
Now, a simple explanation of the difference is that North American 220 v power is a three wire system with two 110v power lines and one ground. North American is 60 hertz. European is also a three wire system, but it has one power line, one neutral, and one ground. Thus the single power line transmits 220v power. (This is similar to North American 110v.)
Note Peaks (Boat Yard) in Grenada has 110v power but it is 50 hertz. Don't know about St. David's. If my memory is correct the small marina in Prickly Bay is 220v European.
What do you do? I cannot suggest you use adapters to plug European shore power into your main panel without an isolation transformer. More than likely this would be a major problem unless your panel is wired to isolate the input to solely the charger. Figure out how to power a charger and then use your inverter. Thus the separate 30 amp shore power inlet by passing the main panel.
It is easy to make your own adapter - plug that is. Buy a North American 30 Amp plug and a European 16 amp plug. Both are three wires. Just wire normal, the European will be marked L (load/live), N (Neutral) and G/E (Ground). Connect these to the North American equivalents. I don’t believe you will find a commercial adapter, too much risk (liability).
