 In 1968, Nygren became the commanding officer of "Surveyor" while she was operating in Cook Inlet, and with him in command, she conducted pioneering geophysical surveys of gravity and magnetism – prototypes for future studies of the continental shelf – between Hawaii and the United States West Coast before returning to the Bering Sea, where she conducted operations as far north as Cape Prince of Wales.Promoted to the permanent rank of captain while in command of "Surveyor", he turned over command of her to his successor in August 1968 in Nome, Alaska.Promoted to rear admiral, Nygren became Associate Administrator of ESSA in October 1968.