If you are talking about the 3220 it is 48V. There are some 12V/48V DC/DC converters but they are pretty expensive but you can hard wire them into the house supply. Powerstream has one:
12 volt DC/DC converters regulator from 100 to 700 Watts. Search form PST-DC1248
It is a little noisy in a couple of the marine SSB bands though.
Some of the POE injectors have a ground wire clip that gives some limited protection from lightning pulses if you tie it to the boat's lightning ground but in my experience just kiss all your electronics good bye and consider yourself lucky if any survive.