(CNN) — Some off-duty public safety workers ended up with an unusual catch when they went fishing off the coast of Florida on Saturday morning.

They found a man and woman splashing in the water 7 miles from shore who said they’d spent the last 14 hours treading water, the Broward County Sheriff’s Office said.

Sean McGovern, 50, and Mellisa Morris, 52, said they’d fallen off their boat in Key Largo about 6 p.m. Friday. The boat was in gear, and they watched it pull away from them, the sheriff’s department said.

“They are very lucky — they didn’t have any signal device,” said U.S. Coast Guard spokesman Mark Barney. “They were trying to signal people down with their T-shirt. To be located and recovered by off-duty cops and a firefighter — that’s a stroke of luck right there.”

About 8 a.m. Saturday, two Broward sheriff’s detectives, a Broward firefighter and one of the officers’ father-in-law noticed splashing in the water from their boat, the sheriff’s department said.

“We saw birds diving,” said Adam White, a detective. “As we got closer, I saw fish jumping. We saw a white male with his shirt flagging us down.”

The men pulled McGovern and Morris onto the boat. They were exhausted after drifting 10 nautical miles and appeared to have mild hypothermia and jellyfish stings, the sheriff’s department said.

“We checked them out, made sure they were stable,” White said.

The fishermen passed them over to the Coast Guard, which carried them to the Fort Lauderdale Coast Guard station. Friends picked them up there.

“A lot of people don’t wear life jackets because they don’t have intention of being in water,” Barney said. “It was a miracle they were able to tread water that long and were safely recovered.”

White summed it up: “They’re pretty lucky.”