Craig Hosmer, 67, a California Republican who became a leading advocate of nuclear power during 22 years in the House of Representatives, died of a heart attack Oct. 11 aboard a cruise ship bound for Ensenada, Mexico. He lived in Washington.

Mr. Hosmer was the ranking Republican on the House Interior Committee and the Joint Committee on Atomic Energy. In 1975, when he retired from Congress, he became the founding president of the American Nuclear Energy Council, a nuclear power trade association. Since 1979, he had been of counsel to the Washington law firm of Doub and Muntzino.

During his years in Congress, he was a proponent of the construction of nuclear powered aircraft carriers. He also was one of the principal architects of the Colorado River Basin Project, a measure enabling California to obtain added water for its growing population, industry and agriculture.

He was an adviser to the U.S. Atoms-For-Peace delegation at Geneva and the 18-Nation Disarmament Conference. He was honorary chairman of the 18th annual meeting of the American Nuclear Society in 1972.

Mr. Hosmer was a 1937 graduate of the University of California at Berkeley. He earned a law degree at the University of Southern California in 1940. He was a Navy officer during World War II, serving in the North Atlantic, Alaska, Iwo Jima and Okinawa. He was commander of an assault transport at the war's end.

He retired from the Navy Reserves in 1973 with the rank of rear admiral.

During the late 1940s, he was a lawyer with the Atomic Energy Commission at Los Alamos, N.M. In 1950, he returned to his native California and ran for the House of Representatives. Narrowly defeated, he was elected in 1952 to the first of 11 consecutive Congressional terms. His district included Long Beach and western Orange County.

Survivors include his wife of 36 years, the former Marian Swanson, of Washington; a son, C. Larkin, of Walpole, Mass., and a daughter, Susan Hosmer of Denver.