When it comes to your boat's electrical system, you have many options. The main options are batteries, plugs and shore power. These options are not always the safest, and are not always supported by good engineering. It's best to take some precautions, like using a smart boat charger to charge your batteries while you're out on the water. There are also many maintenance battery chargers available.
A good marine plug is made from a material other than brass. This includes nylon and stainless steel, though the latter is the best choice if you plan to use below the waterline. Nylon is a good choice because it won't crack, unlike copper.
