I was wondering what was the best bridge to catch shark at in the Florida Keys, I live in Marathon and am wanting to try and catch one. Also what kind of rig and bait.

I have caught sharks on most of the bridges in the Keys. My favorite is Channel 5 and Long Key. I have caught monster Lemon Sharks on the south side of 7 Mile bridge. Several others have caught hammerhead from there too. Mono main line to mono heavy leader to wire leader. Depending on your size bait will determine if you need to do a stinger rig. I don't recommend doing stinger rigs if you are fishing from the bridge. When you release the shark the hooks are still on it. I don't like have two hooks lodge deep in it mouth. I use jacks and bonito for bait. Even fish carcass from the fish market will work.

7 Mile and Long kEy

+1

I think double hook rig's have been baned for shark. Not at all certain about this. But you may want to check to be sure.

Where can you get bonita?

Check the charter/drift boat docks. You can usually get them for cheap or trade some beer to the mates for them.