The capsized sailboat of a missing participant in the Water Tribe

Everglades Challenge was found by U.S. Coast Guard units off Sanibel Island Tuesday. The boater, Jim Slauson, remains missing.

The Coast Guard suspended its search for Jim Slauson, 73, a missing mariner who was participating in the Water Tribe Everglades Challenge. 

The search for the St. Petersburg man ended

The Coast Guard used assets from Fort Myers Beach, Clearwater, the Coast Guard Auxiliary Air Patrol, Florida Fish and Wildlife Conservation Commission and the Collier County Sheriff's Office during the several-day search.

The effort started Monday after the Coast Guard St. Petersburg command center received a report from Slauson's son that his father was off-track of the organized event path. His last personal tracking device check-in was at 7:24 a.m. Monday. 

A Coast Guard Air Station Clearwater aircrew located Slauson's blue, 17-foot Core Sound sailing vessel Monday evening. A Clearwater Jayhawk helicopter crew found no one aboard.

"Suspending a search and rescue case is one of the toughest parts of the job," said Capt. Matthew Thompson, commander of Sector St. Petersburg. "Our thoughts are with the family during this difficult time."

Since the search began on Monday, Coast Guard air and surface units conducted over 46 searches covering more than 9,772 square nautical miles. 

Slauson, originally from California but was now living in the St. Petersburg area, was participating in the Water Tribe Everglades Challenge. The challenge is a roughly 300 nautical mile, unsupported, expedition-style adventure race for kayaks, canoes, and small boats with a time limit of eight days or less. The route goes along the coast from St. Petersburg to Key Largo.

Slauson's sailboat was last tracked to somewhere near Sanibel, race organizers said. On Monday, the race website's course plot listed him  "way out in the Gulf off Keewaydin Island heading SW for the last 6 hours moving 2 kts at 6:01 AM."

Organizers said weather at the time was bad for a boat that size, with 20 to 30 MPH winds and 4 to 7-foot seas.

The Coast Guard alert initially described Slauson as disoriented. When found, his sailboat was capsized.