Reverse polarity is not only an electrocution hazard, but can also damage electrical equipment. Never trust the power supply at strange docks, but always check the polarity. When hooking up to strange docks, always check your volt meters to make sure you have adequate voltage. Low voltage is very damaging to electrical equipment. Turn on the stove or water heater and watch what happens to the meter.
Many people think that the circuit breakers on the dock protect their boat.
Your main circuit breaker protects your boat's systems. Well, the fact is that it is unprotected. Check out all the top end boats and you will find that they have circuit protection located directly at the shore connectors. Which is why we recommend that you should too. Having slow blow cartridge fuses installed directly at the connectors can go a long way toward preventing fires and burned up shore cords, particularly if you are a traveler and frequently rely on uncertain power supplies.