NAPLES, Fla. (WFLA) — The U.S. Coast Guard said it has suspended its search for a doctor who went missing off the coast of Florida.

The Coast Guard said Dr. Chaundre Cross was last seen Tuesday while visiting the Naples Bay Resort and Marina on his boat, the “Vitamin Sea.”

Thursday, the Coast Guard said it found the boat between Sanibel Island and Naples, but Cross was not on board.

For days, air and sea crews searched for Cross, who was believed to be somewhere in the water. The Coast Guard said crews covered an area of approximately 13,100 square miles over the course of 100 hours.

“It is always a difficult decision to suspend a search and rescue case,” said Capt. Michael Kahle, commander of Sector St. Petersburg. “Our deepest sympathies and condolences go out to the family and friends of Dr. Cross during this difficult time.”

The Coast Guard said the Florida Fish and Wildlife Commission, Collier County Sheriff, Lee County Sheriff and Naples Police also contributed to the search efforts.

The Coast Guard asked anyone who had information on potential leads to call 727-824-7506.