Believe it or not, locking yourself inside a metal cage and going underwater with a bunch of gigantic, hungry, scary-looking great white sharks can actually be pretty good for the sharks.

Well, most of the time.

“Great white sharks would not still be around if not for cage diving in South Africa,” said Austin Gallagher, a postdoctoral researcher at the University of Miami who focuses on predators. “They would be hunted, fished, and poached. The only reason they are able to survive is because tourism operators there are generating a lot of socioeconomic benefits.”

The tours generate income, keep people employed, and funnel money back into both conservation and the local communities. “That’s a good thing,” Gallagher said.

That said, this kind of ecotourism can also be extremely harmful to sharks when done improperly. A handful of great white shark tourism operators drag the sharks into cages, causing damage to their bodies or teeth.

Other species have also been harmed. Studies have documented whale sharks covered in scars from boat propellers. Other species have seen their feeding habits disrupted or have changed what part of the ocean they swim in as a result of tourism operations. In the one area of the Bahamas, tiger sharks have started to roll over on their backs whenever they see people, a response to one operator who frequently flips them over and puts them in a state of temporary paralysis called tonic immobility.

“You’re leaving the resource in a way that’s worse than when you found it,” Gallagher said. “That’s not good stewardship. That’s not ecotourism.”

Despite the risks to the animals, Gallagher speaks highly of most shark-tour operations. “Everybody should experience sharks,” he said. “But there needs to be accountability.”

A new paper by Gallagher and a team of shark researchers could help to create that accountability. The paper, published this month in Conservation Biology, examines previous research about shark tourism and found that, if done properly, it can be beneficial both to some of the big, charismatic shark species and the people who live near them.

Part of the key, the researchers wrote, is creating a voluntary code of conduct for tourism operators and a public feedback mechanism to rank them—think Yelp or TripAdvisor for sharks. The researchers proposed just such a system: It would score tourism operations on their educational content, their safety record, how well they treat the animals, their environmental sustainability, and conservation ethics.

“We’ve got something like this in almost every other aspect of the tourism world,” Gallagher said. “What it’s going to do is hopefully weed out bad operators.”

Conservation groups have already praised the ideas posed in the paper.

“Sharks are demonstrably worth far more alive than dead,” said Imogen Zethoven, director of the global shark conservation campaign at The Pew Charitable Trusts. “This study represents the most comprehensive snapshot to date of the potential for shark-dive tourism to serve as a lever for protection of these globally threatened species.”

So far voluntary codes of conduct only exist for tourism related to one species, whale sharks, and that hasn’t been completely successful. A study conducted 10 years ago found that the majority of divers still got too close to whale sharks, and 18 percent of them disobeyed requirements to not touch the big animals.

Gallagher said he is hopeful that future standards will enjoy greater acceptance and compliance. Until then, he recommends that people look for tourism operators with good safety records who give back to their local communities and promote sustainability.

And if you go so far as to get into the water with sharks, Gallagher has three simple words of advice: “Look, don’t touch.”