I am starting my research for a depth finder. I want to be able to tell bottom comp, structure, cover, thermocline, and in some instances, fish. I like the color coded ones. I am also looking for GPS in the unit and at a decent price (not a cheapo). I want a quality unit that will last. If there are any other issues I should be considering, let me know. Any suggestions?

P.S. This will probably be a used purchase. So your suggestions do not need to be for the newest models unless they are what you believe in. Thanx guys!

LMS 332C. http://www.lowrance.com/Marine/Products/LMS-332C.asp  $600-$650, including antenna and NMEA 2000 network, regular bracket incl, $30 for a RAM mount.

I run two, one on the bow, the other console mounted. Each has its own GPS antenna mounted over their respective transducers. Highly accurate, dependable, can record sonar sessions, can be plugged into the tow vehicle using magnet-mounted antenna (best), or antenna on the dash (less accurate). Great customer service by phone. Put it through the test before warranty expires. If ANYTHING goes wrong or sub-par get an RA number and send it in about now or in the cold of winter.  That's a cheap way of extending the warranty period. If nothing was wrong at least you get a good checkup pretty cheap, and they'll make sure it's updated and in peak performance.

Jim

try a Garmin 2006c, with GPS capability, you have everything you need with this unit. we run one on our triton Tr 21 and it has every feature you need.