As of Thursday morning, rescuers had searched more than 40,000 square nautical miles, said 2nd Class Petty Officer Anthony Soto, a Coast Guard spokesman. That's an area roughly the size of Arkansas.
The Coast Guard will continue searching the ocean off more than 400 miles of coastline between Daytona, Florida, and Myrtle Beach, South Carolina, he said.
Candles and lanterns lit the sky Tuesday night along the beach in Stuart, a short distance from Jupiter Inlet where Perry Cohen and Austin Stephanos were last seen on their 19-foot boat.
The hundreds who joined the vigil made it clear that they hadn't given up hope.
Organizer Cory Ritz told CNN affiliate WPEC
that as the parent of two children, she feels the pain of the families.
"I can't even imagine," she said.
Isabella Murgio, a friend of the boys who organized the vigil, said the community wanted to show belief that the boys are still alive.
"I've never seen the inlet packed like this," she said Wednesday on CNN's "New Day."
Another friend, Mathew Lavallee, said one of the boys posted "Peace out, Jupe" on Snapchat before they left.
"I don't know what that meant to them," Lavallee said, "but I think they just went out fishing and saw the storm and decided not to come in, thought they were invincible and could conquer it."
The outpouring of support came as the search for the two 14-year-olds expanded up the coast.
The U.S. Coast Guard said it was searching an area off Tybee Island, Georgia, again Wednesday morning after reports of an object in the water. It looked last night but wanted to try again in the daylight. Based on the computer models the Coast Guard is using, this is not an area where the teens are likely to be found.
"It's a huge area," Capt. Mark Fedor of the Coast Guard said Wednesday. "However, we are having that discussion of when we should suspend the search. And that is a gut-wrenching decision. We are looking at all aspects of the case, but that is something we have to talk about as we move forward."
The Coast Guard estimates that someone could survive in the warm Atlantic waters for up to five days this time of year. The boys were last seen Friday.
A private search effort is being paid for by a GoFundMe campaign
. The Perry and Austin Rescue Fund has raised more than $144,000 to pay to fly private aircraft and buy boat fuel.
The Coast Guard has had five cutters, a Navy ship and multiple planes involved in the search.
The situation has grown increasingly dire since the boys' capsized boat was found Sunday, but their families are not giving up hope.
"We are 100% committed to finding and rescuing those boys, as is the Coast Guard, and we will not stop until we get them back home with us," Perry's mother, Pamela Cohen, told CNN's "Erin Burnett OutFront" late Tuesday.
"We just feel very, very confident that they will be able to stick through this. They know that we're coming for them and we will get them," she said.
Austin's mother, Carly Black, is counting on the teens' boating expertise.
"These boys have been out there doing this forever. It's not new to them," she said. "They prepare for these situations."
While the boys are young, they were legally operating the boat. Florida regulations say a person must be at least 14 to operate a watercraft.
Football great Joe Namath, a neighbor of the boys' families, is among the friends supporting them. He also said he's optimistic.
"The history of the high seas have survival rates over the years," Namath said. "There have been miracles out there, and we're planning on finding the children."
Keith Judy is one such survivor. He and a friend spent 20 hours in the ocean with his son and the son's friend on July 13 after their fishing boat capsized off Charleston, South Carolina, Judy said Tuesday on CNN's "New Day."
He said the group tied itself together with a rope and hung onto a floating cooler through the night.
"Before the Coast Guard found us, the sharks started bumping us and swimming through our legs and actually hitting our skin and cutting our skin," Judy said. "We fought off small sharks for a little while."
Judy said he got the attention of a Coast Guard boat by standing on the cooler and waving a life jacket.
The search area
Austin and Perry were last seen Friday near Jupiter buying $110 in gasoline for their boat, Coast Guard Petty Officer 1st Class Steve Lehmann said at a news conference.
About the same time the boys were heading out to sea, the National Weather Service was posting special marine warnings telling boaters to seek shelter.
"It doesn't take much when you are off shore," said CNN meteorologist Jennifer Gray. "Storms will pop up and the seas will build very quickly."
The teens' boat was found Sunday, capsized 67 nautical miles (about 77 miles, or 124 kilometers) off Florida's Ponce de Leon Inlet, well north of Jupiter.
The search pattern has spread northward with the passage of time and the flow of the Gulf Stream.