OPA-LOCKA, Fla. — After hundreds of rescue workers fanned out across a massive swath of the Atlantic for a full week, the Coast Guard’s search for two teenage fishermen ended Friday, a heart-rending decision for families so convinced the boys could be alive they’re pressing on with their own hunt.

Even as officials announced at noon that the formal search-and-rescue effort would end at sundown, private planes and boats were preparing to keep scouring the water hoping for clues on what happened to the 14-year-old neighbors, Perry Cohen and Austin Stephanos.

Capt. Mark Fedor called the decision to suspend the search “excruciating and gut-wrenching.” He suggested what long had been feared by observers – that the boys had surpassed any reasonable period of survivability – with his offering of “heartfelt condolences.”

“I know no statistics will ease the pain,” he said in recounting the seven-day, nearly 50,000-square-nautical-mile search. “We were desperate to find Austin and Perry.”

With volunteers ready to keep searching all along the coastline and about $340,000 in search-fund donations by Friday evening, the families promised to keep looking for their sons. Those who have met with the families believe the private search could go on at least for weeks.

“How could you go back to normal?” said Tequesta Police Chief Christopher Elg.