Ralph Samuel Waters, 81, a retired official of the St. Mary's County, Md., public school system and pastor of St. Mary's Larger Parish, a Methodist church, died of congestive heart failure Aug. 12 at North Arundel General Hospital in Glen Burnie, Md.

Mr. Waters, who lived at the Crofton Nursing Home in Crofton, Md., was born in Clara, Md. He graduated from Morgan State College and later took a master's degree in education at New York University.

He began his teaching career in Wicomico County, Md. In 1934, he moved to Leonardtown, Md., and joined the St. Mary's County school system. He became principal of the Jarboesville School and was a supervisor in the school system when he retired in 1966.

He was pastor of St. Mary's Larger Parish from 1941 to 1969.

Mr. Waters, who lived in Bowie before moving to the Crofton job, was a Mason and an Elk and a member of the National Education Association, the Maryland State Teachers Association and the NAACP.

Survivors include his wife, Louella, and a daughter, Sandra McDonald, both of Bowie; two sisters, Letta Hull of Salisbury, Md., and Lela Larmore of Tysaskin, Md.; two brothers, Paul of Salisbury, and the Rev. James O. of Brandywine, Md.; and one grandchild.