Looking to purchase a GPS/Chartplotter device for my boat. I know the reefs are a killer at the coast. Which system do you feel is the best to purchase?

Not one of them shows all the reefs and rocks and such. I've found most brands to be about the same in the amount of detail. I have a Lowrance on the bay boat and a Garmin and Furuno on the big boat. They all have about the same detail. The Lowrance has some nice features the Garmin is the easiest to use and the Furuno just makes me mad, it stays in FF mode. I've never used the Hummingbird, I'm from the west coast and they're considered a kid's toy there. When in new to you territory the best bet is to be on the lookout and when you find something then add it to your waypoints. Texas Saltwater Fishing magazine has a pretty good write up about this very thing. Not a bad read.
joe

Pretty much dead on. Your eyes will mark reefs just before you hit them. Never shows up on GPS. I do use my GPS to mark spots and navigate in the fog.

Any of them will work fine for inshore fishing. For offshore I'd look at Simrad and Garmin for navigation and Furuno for the sounder. Had Raymarine on my last boat and it was decent but I never could get the FF to pickup bottom once I got over about 20 knots.

If you are going to use it offshore I'd recommend a thru-hull sounder over the transom mount transducer. It'll work mo' better at speed.