I will add my 2 cents as a former shark feeder in Freeport, and someone who has done limited research the subject academically. The sharks that we fed did not show up every day as Mike notes, though there were usually at least one or two around in the afternoon. The sharks fed normally at night and in the morning, with most sharks getting one fish during the feeding. We never advertised the sharks as cute or cuddly, that's why I wore armor, and extensively warned people about sudden movements with their hands.
I do not think that equating shark feeds to feeding bears is accurate. A hiker looks like any other person walking outside, and a bear will learn to associate people with food. A scuba diver does not generally resemble a human to a shark. All of the metal will give a shark a different electrical sense of a diver than a swimmer, and this is doubly true for chain mail divers. In addition, the bubbles create noise and several things contribute to divers not looking like normal swimmers. My evidence fro alll of this is merely my experience, albeit limited. I never witnessed or heard about a shark even noticing normal divers off of freeport, and they usually swam away when divers entered the water. Sharks would approach a diver clad in chain mail, but would swim away if food was not present. When food was present, the sharks only paid attention to the feeder, and ignored everything else in the water.
The only shark attack of a swimmer off of Freeport that I know of, was by a BUll shark near shore. While several hundred yards from the site where the sharks were fed, I never heard of a Bull shark attending a feed conducted by any of the shops. And yes, we did trade stories, including when where a tiger showed up one morning during a staff only practice. Nothing happened.