MARATHON, Fla. — A Missouri man died while snorkeling in the Florida Keys on Christmas Day.

Monroe County Sheriff’s spokeswoman Becky Herrin said in a news release that 69-year-old Owen Holmes of Ozark, Missouri, was visiting the Keys with his family over the Christmas holiday. He began to have problems Monday while snorkeling near the Sombrero Lighthouse.

Herrin says the crew brought Holmes on board the boat, operated by Starfish Snorkeling in Marathon. The U.S. Coast Guard responded to the location and took Holmes to shore. He was pronounced dead at Fisherman’s Hospital.

According to the release, Holmes had a number of medical conditions and there was no sign of trauma or injury.

An autopsy will be performed to determine the cause of death.