There are boats all over Key West that will take you out on the ocean for a day of fishing. In the evenings, you can go by the harbor and walk along the charter dock to compare prices. We found that plenty of captains were available to go out the very next day. We, however, had brought our own equipment and decided to strike out on our own in search of a great fishing spot. Armed with non-resident licenses from the local K-mart, we took to the road.
We tried the pier, but were sorely disappointed--not even a nibble--for several days before moving on. My Dad tried a little fishing from Houseboat Row, but still no luck. Our best day was the day we got up early and started driving back up US 1. We would stop at pull-out areas and bridges--anywhere that one of us said "looked good"--to try our luck. We found a great spot by an old bridge to Cudjoe Key. We were hoping for some tarpon, but started out catching mostly little guys--fish that looked like they''d come out of an aquarium. I climbed down by the side of an old bridge and into some mangroves closer to the water and had some great luck there while enjoying the view. The water was shallower and clear enough that I could watch the fish go by; I kept attempting to entice a lobster I could see on the bottom, but he wasn''t interested.
We soon found ourselves staked by an egret hoping for a handout. He eagerly slurped up any of the fish that wriggled out of our hands, so we had to shoo him off. All in all, it was a great day and we had lots of fun. (We had to make a speedy return to give back the rental bikes.)
My recommendation is to strike out on your own and find someplace with a little peace, a little scenery, and a lot of fish. The Keys are full of them and hey . . . bait is cheap.