(CNN) -- Volunteers and veterinarians caring round the clock for stranded pilot whales were buoyed Saturday evening by news that two were released off the Florida Keys.
After being transported by boat, the males swam away in the Atlantic Ocean about nine miles off the lower Florida Keys shortly before 6 p.m., said Karrie Carnes, National Oceanic and Atmospheric Administration spokeswoman.
The pair are 12 feet and 13 feet long and weigh more than 1,000 pounds each. They are considered teenagers.
Five other surviving pilot whales are being cared for in a sea pen established at Cudjoe Key, about 20 miles east of Key West.
"They (the whales) are being literally cradled 24 hours a day," Carnes said.
Fourteen whales died after stranding themselves in shallow waters over a 12-mile stretch of sand flats.
Veterinarians are not sure why the protected whales came to shore, said Carnes, adding that they are usually found in 300-meter deep waters in the Atlantic and the Gulf of Mexico. "We may never know why this group stranded."
The pod showed no evident signs of significant emaciation or illness, but may have become disoriented and followed each other to the shore.
"They are very social animals," Carnes said.
The rescue effort, which began Thursday, has included hundreds of federal and state employees, veterinarians and volunteers, said Carnes, who works at the Florida Keys National Marine Sanctuary.
Rescuers plan to transfer the five survivors to a rehabilitation facility in Key Largo once they are healthy enough to undergo the journey, Carnes told CNN.
Tents and wet sheets are protecting the five from the sun and temperatures. Veterinarians are checking their blood and body fluids and are pumping them with antibiotics and enzymes.
Volunteers from the Marine Mammal Conservancy in Key Largo have been crucial to the operation.
"For a lot of people, marine animals are very charismatic," Carnes said. "People have a love of the ocean and mysteries of the deep."
Sea World, the U.S. Coast Guard and the Florida Fish and Wildlife Conservation Commission also have provided assistance in the lifesaving effort.
Adult pilot whales can measure up to 20 feet long and weigh up to 3 tons. Due to their social nature, they are often involved in mass strandings, according to the American Cetacean Society. The ACS is a nonprofit group based in California that works to protect whales, dolphins and porpoises, according to its website.
A similar incident occurred in the Florida Keys in 2003, when 28 whales were stranded. Most of them died, but after several months of care, five were released back into the ocean.
CNN's Lateef Mungin contributed to this report.