Raymond H. Baetsen, 48 a retired Coast Guard captain who was an expert in recreational boating safety, died of leukemia Thursday at the Bethesda Naval Medical Center.

Capt. Baetsen was assigned to Coast Guard headquarters in Washington from 1968 until his retirement in 1976. During those years he helped develop national standards for pleasure-boat safety and became a recognized authority in the field.

Earlier in his career, he had taken part in the development of electronic navigation systems and in the Coast Guard's "vessel traffic services." This is a system by which ship traffic is controlled in major ports.

Capt. Baetsen was born in Green Bay, Wis., and grew up there. He graduated from the U.S. Coast Guard Academy at New London, Conn., in 1952. He later earned a master's degree in electronics engineering from the Naval Post-Graduate School.

His early assignments included command of a navigation station in the British West Indies and then of a Coast Guard cutter stationed in New London. From 1964 to 1968, he commanded the Coast Guard electronics test center at Longwood, N.J. Since retiring from the Coast Guard he had been a private consultant.

He was a member of Sigma Xi, an honorary scientific society; the Electronics Engineering Society; the Institute of Radio Engineers; and the American Boat and Yacht Council.

Capt. Baetsen held the Coast Guard's Meritorious Service and Commendation medals and the Achievement Award of the secretary of Transportation.

He was a member of St. Catherine Laboure Catholic Church in Wheaton and had been a troop leader in the Boy Scouts.

Survivors include his wife, Mary, of the home in Kensington; two sons, Kevin, of Fairfax, and Steven, of the home; and a sister, Elaine Ropson, of Green Bay.

The family suggests that expressions of sympathy be in the form of contributions to the Leukemia Society of America, the Webb Institute of Naval Architecture Parents Fund, or to the National Naval Medical Center in Bethesda.