Many nocturnal predators (nurse sharks, jacks, tarpon, ...) have learned that divers have lights, and that many of the things that divers like to look at with their lights are good to eat. Thus, we are often followed around. For the entire hour of the dive, this shark (and one other) were always around, often swimming through my legs. I could have reached out to touch it many times, but sharks are definitely on my "don't touch" list. If they choose to come that close to me, that is one thing (and I have been bumped and nudged occasionally), but pushing the encounter further is "not a good idea": they have no interest in divers as food, but they are wild animals and we are guests in their home.