William K. (Billy) MacWilliams, 53, a former restaurant owner in North Beach. Md., died Tuesday in Punta Gorda. Fla., after a heart attack. He had moved there a year ago after retiring because of ill health.

Mr. MacWilliams had owned Uncle Billy's and The Reef in North Beach and had lived in Chesapeake Beach. He had been in the restaurant business in the two Caivert County resorts for 30 years.

In 1955, along with George L. Kellam Jr., Mr. MacWilliams was awarded the bronze medal of the Carnegie Hero Fund Commission for rescuing six persons from a sinking vacation schooner in Chesapeake Bay.

The two had braved Hurricane Connie in August of that year in an 11 feet, motor-driven skiff to rescue survivors of the sinking schooner, the Levin J. Marvel. Fourteen persons on the schooner died.

In addition to the Carnegie award, both men received honors from Maryland Gov. Theodore R. McKeldin, the commandant of the Coast Guard and the people of North Beach and Chesapeake Beach.

Mr. MacWilliams was born in Welch, W. Va., and moved to Calvert COunty in 1933. He served with the Navy in the Pacific in World War II.

In the early 1950s, he was one of 11 persons convicted of participating in the notorious Charles E. Nelson numbers operations at a trial in District Court here. However, he was one of five defendants who were cleared when the U.S. Court of Appeals later overturned their convictions.

Mr. MacWilliams had been a member of Elk Lodge No. 15 in Washington for 30 years.

He is survived by his wife, Judith, of the home in Punta Gorda; a daughter, Virginia Mae Lusby, of Prince Frederick, Md.; four sons, William, of Phoenix, Nelson, of Washington, and CHarles and Richard, of Calvert County; a brother, Heber of Churchton, Md., and threegrandchildren.