Which sharks are people able to swim with safely?
Short answer: none of them.
Longer and more nuanced answer: All sharks have the ability to hurt you. Whale sharks are considered very friendly as sharks go, and have been known to play with divers, but they’re also ginormous. Even sharks that are accustomed to humans still pose a risk- they’re wild animals with the capacity to hurt someone, and just because they haven’t hurt anyone yet doesn’t mean they never will.
That said: many organizations will offer diving tours to swim with sharks. They have a pretty big incentive to not have people get hurt on those tours, so they likely put a lot of work into making the experience as safe as possible. Injuries (and deaths) when swimming with sharks in a “controlled” environment are very rare. There is always a risk, but that risk is typically minimized. I personally am too afraid of that risk, however small it may be, to probably ever try it, but if that is something you (or anyone else) is interested in, the risk factor should not necessarily stop you. I’d recommend doing some research into a particular program, because safety information will be specific to the area and the types of shark you’re expected to encounter.
And I will absolutely recommend very strongly against swimming with sharks outside of this kind of controlled environment- that is very much not a safe thing to do.
[Again, apologies for typos/incoherencies]
If you don’t mind me butting in with my own two cents, nurse sharks are generally what organizations like this will let you swim with, as they are deemed one of the “safer” species to have large groups of people around (Lord knows the one or two guides can’t keep an eye on everyone 24/7, especially if they’re focusing on, say, a kid). In addition, nurse sharks suck prey into their mouths more than bite it (much like sting rays, actually, and I’ve fed both), so its much harder to be bitten when properly instructed on how to feed these sharks, or even just interact with them. They’re one of the few sharks that I’m more than willing to jump right in with because I’ve had the opportunity to be around them before, but that doesnt mean I’m saying they pose no threat at all and that you should approach one you MIGHT think is a nurse shark. OP is very right, all sharks have the ability to be dangerous, and you very much should look into the companies that do these little excursions before deciding, but it is important to know that most companies (unless they are really off their rockers and are therefore pretty sketchy right off) will never take people near sharks that are ‘known’ for being particularly agressive or dangerous, unless you have a scuba diving licence and are going with a well experienced instructor/guide, and even then most won’t take you to dive with, say, lemon sharks which have been characterized as a very aggressive species last I heard, or giant great whites.
Some options are better than others, and you should indeed remember that they are wild animals still, but most sharks in “commercially safe” areas are kinda like bees; respect them and they’ll leave you alone. They might swim by out of curiosity, or because they’re being fed, but most of the sharks that are “used” for this are all very used to people and just stick around for the easy food.
