While I had my panel apart the other day, I noticed the RJ jack in the back
of the 302. Since I had half a Cambridge cable, I plugged it in, powered
up, and measured voltage across the red and black leads - 5v!

I took a standard USB cable that fits the Mio, cut it, and measured the red
and black leads - again, 5v! Tomorrow, I'll connect the two cables together
and run the Mio of the ship's batteries.

Dan