Hawaii is grappling with an alarming increase in snorkel-related deaths. Ten people have died since January. On average, 17 people die each year in Hawaii while snorkeling.
A full-face snorkel mask is at the center of one theory about the rise in deadly incidents. So far this year, that type of gear has been involved in four deaths.
Lifeguards say they are seeing more and more of the full-face snorkel masks. Some tourists CBS News has spoken to say they love them because they're easier to use than conventional mask and snorkels, reports CBS News correspondent Vladimir Duthiers. But safety experts warn there are risks associated with them that people may not know about, and for one man's wife, that warning came too late.
Guy Cooper and his wife, Nancy Peacock, traveled the world together. But on her last trip to the Hawaiian islands, Cooper stayed behind at their home in California. He said it haunts him every day.
"I picture her in the water, frightened, panicking, and trying – struggling with that mask," Cooper said.
An avid snorkeler and a "good swimmer," Peacock was trying out the full-face mask she bought on Amazon. But less than an hour after entering the water, her lifeless body was pulled out by a nearby surfer.
"I started right away thinking about this mask," Cooper said. "Well, 'cause I'm trying to think what – what could have gone wrong."
The masks have a new design that covers the entire face, allowing snorkelers to breathe out of their nose and mouth, unlike the traditional two-piece snorkel equipment.
But some safety experts say it's the design that may make it less safe with greater risk for carbon dioxide buildup that could cause snorkelers to become dizzy or disoriented. Tighter-fitting head straps also may make it harder to pull off in an emergency – something Cooper suspects happened to his wife.
"I wrote to the coroner and I said, 'Wouldn't you want to know what she was using? … The ER never asked those questions, you never asked those questions, apparently no one is asking those questions, and couldn't that be a contributing factor?'" Cooper said.
But until last year, the type of equipment used in snorkel-related deaths or near-deaths was never recorded.
"No one will know if they're dangerous or not until you put it in a database, look for trends," Cooper said.
Ralph Goto recently retired as Honolulu's director of ocean safety after 30 years. He now co-chairs a committee investigating the spike in snorkel-related deaths along with the Hawaii State Department of Health.
"There's the full-faced mask theory. There's issues of pre-existing medical conditions. There's theories of inexperience and all of them have some credence," Goto said. "So we're asking first responders to gather the equipment involved in these cases."
Lifeguards like Kawika Eckart said "more and more people" are using the full-faced masks. He and his team are responsible for the safety of an average of 2,600 visitors each day at Hanauma Bay. He said it's too early to know if they put snorkelers in greater danger.
"We're looking into… if there is a connection to snorkel drownings and the full-face mask," he said, adding that he's tried the masks himself.
"And what'd you think?" Duthiers asked.
"No comment," Eckart said.
One manufacturer of the full face masks, Head USA, said in a statement: "The safety of our customers and the performance of our equipment have always been our first priorities," adding the product "was put through rigorous testing protocols…including the measurement of potential CO2 build-up." The statement went on to say their success "has spawned a number of low-cost copycat masks... whose expertise, design and manufacturing experience are unknown."
It's something that troubles Robert Wintner, founder of Snorkel Bob's, one of Hawaii's top snorkel equipment retailers.
"I get three or four inquiries a week from Chinese manufacturers. 'You must carry these. Please send your address. We'll send samples.' And my response is always the same, 'No, thank you. Please put them in the dumpster,'" Wintner said.
Wintner decided against carrying any of the full-face masks after his researchers tested them.
"They said that the face area heats up and gave them a feeling of claustrophobia," Wintner described. "They could not reach their nose to clear. It's hazardous." Wintner said if you try to take the mask off in a hurry and not thinking clearly, "it can stick."
"There were snorkel fatalities way before there were one-piece masks, so I think we need to look at it in totality… is it the snorkel, is it the mask, and we don't know for certain but we are certainly trying to find out," Goto said.
Cooper may never know exactly what caused his wife's death, but for now, he said, "I just wouldn't want someone else to go through what I went through losing her."
Currently, there are no regulations on snorkel equipment in the U.S. The Consumer Product Safety Commission did respond to Cooper's complaint, but they have not taken any actions. Cooper said his wife will not have died in vain if more people become aware of potential risks associated with the devices.