Re: decent color gps/chart plotter and depth
A gps/chartplotter alone will pinpoint your location and, depending on the chart(s) installed, will provide historically recorded depth readings for "the area you are in." If you want real time water depths beneath your boat "right here - right now" you'll need a combination unit (multifunction display) with sonar capability and a transducer. All manufacturers make "decent" multifunction units. Learn what the specs mean, what specs you need for how and where you boat, and buy accordingly. Generally, you get what you pay for.