Geoffrey A. Rabida, 26, one of the youngest chief officers in the U.S. Merchant Marine, died Jan. 26 in an accident at sea about 1,000 miles west of Cape Town, South Africa.

He was the son of Mr. and Mrs. Albert A. Rabida, of Rockville.

Employed by the Interocean Management Corp. of Philadelphia, Mr. Rabida was chief officer of the supertanker SS New York. He previously had been second officer on the supertanker SS Massachusetts.

Mr. Rabida was born in Lisbon, Portugal. His father, now a retired Foreign Service officer, was stationed at the American Embassy there.

Mr. Rabida had attended schools in Portugual, Angola, Ecuador, Brazil and the United States and had lived off and in the Washington area for about 15 years. He was an Fagle Scout.

He received a bachelor's degree in marine transportation from the Maritime College of the State University of New York, and also attended Brooklyn Law School.

For the past five years, he had served as third, second and chief officer on American ships in the Near and Far East Africa, Europe and North and South America.

In addition to his parents he is survived by a brother, Gregory, of Rockville, and his grandmothers, Mary E. Rabida, of Chillum, and Julia Wendrich, of Point Pleasant N.J.

The family suggests that expressions of sympathy may be in the form of contributions to the Boy Scouts of America.