Perry Cohen and Austin Stephanos, both 14, were last seen buying fuel for their boat on Friday

Credit: Courtesy Coast Guard(2)

The desperate search for two missing Florida teens entered its sixth day on Thursday with no sign of the boys.

Perry Cohen and Austin Stephanos, both 14, were last seen buying fuel for their boat near Jupiter, Florida, on Friday. That boat was found capsized on Sunday, about 67 miles off the coast of the Ponce de Leon Inlet. But the teens were nowhere in sight.

The search has now expanded to the South Carolina coast, but officials are beginning to lose hope as the longest anyone has been know to survive in open water is five days.

“We continue to search for the missing boys,” said Capt. Mark Fedor, chief of response for the Coast Guard 7th district. “We’re constantly reevaluating the situation to determine our next course of action, however as each hour goes by, the situation becomes dire.”

Hundreds have rallied to help the boys and their families, holding prayer vigils and taking out their own boats to search. But the stormy waters have hampered the efforts.

However, Cohen and Stephanos have the high temperatures in their favor. “With the water temperatures being a little warmer than typical, a person could survive for four or five days, possibly longer if they hang on to anything that floats,” said Chris Caplan, who’s been searching for the teens in a friend’s plane. “These boys are everyday boaters. They know what to do to survive.”

The Coast Guard has searched an area roughly the size of Kentucky – some 41,000 square miles. But as the days continue to pass, the discussion has turned to when to give up the search.

“That is a gut-wrenching decision,” Fedor said Wednesday, according to CNN. “We are looking at all aspects of the case, but that is something we have to talk about as we move forward.”

For now, though, he emphasized that the search remains “active and open.”

The boys’ families are not giving up either. “The kids are very strong-willed,” Blu Stephanos, Austin’s father, told Fox News.

“They have a Yeti cooler, a 65-gallon cooler, they have three life jackets, a throw cushion, and I know they’ve got the will, they’ve got the want, and they have the skills. So there’s no doubt in my mind that they’re still out there and they’re still waiting to be found.”

Reporting by DEVAN LESLEY