George W. Welker Jr., 78, a retired Navy rear admiral who served in the Pacific during World War II and ended his career as inspector general of the Potomac River Naval Command, died Sunday at a nursing home in Winter Park, Fla. He had arteriosclerosis.

Adm. Welker, who lived in the Washington area from 1939 until 1970, when he moved to Winter Park, was born in Salisbury, Mo. He graduated from the U.S. Naval Academy at Annapolis in 1923. He had various assignments at sea and then returned to the Naval Academy, where he studied communications.

During World War II, he was a communications officer in Washington and then went to the Pacific, where he served aboard the McCauley, a communications ship attached to an amphibious force in the Solomon Islands. He earned the Legion of Merit with combat "V" during this period.

Later in the war, he commanded the Auburn, another communications ship, during the Okinawa campaign and the occupation of Japan. The Auburn received two Presidential Unit Citations while Adm. Welker was her skipper.

Adm. Welker's subsequent assignments included command of the cruiser Quincy, a tour in Washington as superintendent of the Naval Observatory, and command of the Naval forces of the Icelandic Defense Force. He was inspector general of the Potomac River Naval Command when he retired in 1953.

Adm. Welker was a member of the Naval Academy Alumni Association and the Retired Officers Association.

Survivors include his wife, Eleanor C. (Jerry), of Winter Park; a son, George W. III, of Downington, Pa.; two daughters, Mrs. David G. Raher of Bethesda, and Mrs. Richard G. Kline of Arnold, Md., and 10 grandchildren.