Beware of the receptacle wiring, though. This receptacle has two 120V hots (supposed to be opposite legs) and a neutral, giving either 120V hot to neutral or 240V hot to hot. As a boat owner I can tell you that many of these receptacles are wired with two 120V hots of the same phase. This works because most boats do not use 240V, they just want two 120V circuits. So a standard 14-50 adapter will not work with the model S in this situation since it gives zero volts hot to hot, and a modified adapter (using hot-neutral) will only get you 120V at 13A or so, instead of 240V at 40A. You can test it with a voltmeter to see if any combination gives you 240V.
