The Standard Horizon product line includes the CP300i chart plotter and the Matrix GX2150 AIS+ radio. We've had the CP300i chart plotter since 2010. The GX2150 radio is in a box in the V-Berth.
The point of these products is the integration. The chart plotter provides GPS data to the radio and the radio provides AIS tracking information to the chart plotter.
The interconnection is nicely documented in the CP300i and the GX2150 radio installation guides. It's also kind of complicated. It involves a fairly large number of wires.
And. We want to integrate a computer (running GPSNavX). And perhaps a shadow chart plotter at the nav station.
Enter Fritzing (and CadSoft EAGLE). It's relatively easy to lay out the various connections on a PCB board, and then order that board. With relatively little work, the board can be mounted inside the nav station and the wires routed among chart plotter, radio and computer via the custom board. Price is about $36.50 for the board, $5.20 for manual overheads, $8.00 shipping, call it $50.00.
Yes, a simple terminal block is all of $10.00.
A custom PCB seems cleaner than stacking lots of wires on a terminal block. Being able to silkscreen wiring harness labels on the PCB looks like it would make hookup (and diagnosis) slightly easier.