East Hadam is a beautiful town. Look into the brewers marinas in Essex. About six miles up from the mouth of the river. I would also look into places east of the river like New London or Mystic. East haddam is on the east side of the river and all the marinas are on the west side.
But the power to the plotter and the gps are two different things. Look at the GPS as a stand alone item that is simply lacking a screen to view the output. It's powered by a Seatalk connection, not the plotter. By turning off the plotter you simply are no longer displaying the data output...
Every body wants 3 things when the buy something-
Problem is you usually only get two of the three, some time less.
The nice thing is you get to choose which two you get.