New 5200c GPS
I now have a Lowrance 5200c. Found one on clearance, and saved $200.
It took me all day to install in my Discovery. I removed the head liner, so I could mount the GPS module on the roof, using the hole for the factory gps antenna. The unit seems to be identical to the 540c Baja, just not as "rugged".
Boats go over choppy water, so it should hold up to some vibration. I'm not a racer, so it should work for me.