I did the same thing as Greg, using a small DC bus bar. I labeled it my NMEA
Interface with a small diagram pasted next to it, since it looks a bit like the LA Freeway.
Moreover, if you upload WPs from a plotter into a GPS - or vice versa - you might find it handy to install a NMEA plug
at the chart table.
On a related note, just about everyone I bump into plans to use a smaller handheld GPS if their fixed base unit fails...yet rarely do I find someone who's sorted out how the H/H unit will be powered, interfaced AND offer its antenna
to a clear sky since some of these events
must take place belowdecks while the antenna
needs to be topside. Just something to mull on...