There are dozens of wrecks north of Key West. Many are shrimp boats but others are larger vessels. Some of these wrecks are very public and gps numbers for them can be found from a variety of sources. Remember though hurricanes tend to move wrecks so some numbers will not be very accurate.
These wrecks can be loaded with fish depending on the time of year and water conditions. Popular fish to target on these wrecks would be primarily cobia, gag grouper, and various snapper. People often use live pinfish and small blue runners for live baits. People also fish jigs tipped with cut bait or shrimp. A chum slick near one of these wrecks can attract a multitude of fish, sometimes huge schools of blue runners, bluefish and Spanish mackerel, not to mention kingfish. On some of these wrecks, it will be difficult to get a live bait to the bottom before a large lane snapper will eat it.
One issue with fishing these wrecks can be sharks and jewfish stealing a lot of your fish. Using heavier tackle to get your fish in the boat quicker can help a lot. Also if you throw a steel leader on and hook and fight a shark for a while, he and his buddies will tend to leave. Sharks don’t like being around a shark in distress.