Two teenage boys, lost for six days in the Atlantic Ocean in a small open sailboat without food or fresh water, have been rescued off Cape Fear, 180 kilometres from where they started.

A U.S. coast guard spokesperson called it a miracle after fishermen discovered Josh Long and Troy Driscoll on Saturday, exhausted and suffering from sunburn and dehydration, but otherwise in good condition.

During almost a week at sea, the teenagers had nothing to eat and quenched their thirst with seawater. They tried to cool off in the ocean, but sharks chased them back onto their 4.5-metre boat.

A family snapshot shows Troy Driscoll (left) and Josh Long after a less memorable fishing trip. (AP photo)

Long, 18, and Driscoll, 15, knew they were in trouble almost as soon as they set off on a fishing trip from Sullivans Island, S.C., on April 24.

When high winds and a rip tide caught their dinghy, the boys jumped in the water and tried to swim to shore, dragging their boat behind them.

That didn't work, and within hours they were far out to sea.

The boat, a JY15, used by Long and Driscoll. (AP Photo/U.S. Coast Guard)

The boys had lifejackets, but no signalling devices. They shared one wetsuit at night to try to stay warm.

On Sunday, family members gathered at a hospital in Charleston, S.C., to celebrate the teens' safe return.

"I was OK for the first night and second night, but after the second night I thought that we were not going to make it," Driscoll said.

"We lost our tackle the second day, so we couldn't catch any fish."

'A test from God'

"I think it was a test from God, this whole experience was," Long said. "And that was to test my faith and my best friend's faith and the faith in my family."

Every time they saw a boat, the boys stood up, yelled and waved their paddles. One night they woke up to find a container ship bearing down, but the ship's crew didn't see them.

"What we have is an absolutely miraculous story of survival that's going to be studied for years to come," said Long's uncle, Richard Goerling. "Those two boys have a book to write."