Armin Hansen's etchings and paintings of marines, coastal scenes, and the fishing industry of the Monterey Peninsula made him an important figure in American art. He is quoted: "Every move I have made and everything that I have done has always been to go back to the water and to the men who gave its romance. I love them all."

He received his first art instruction from his father, Herman Wendelborg Hansen, 1854 - 1924, the famous painter of the Old West and frontier life. The younger Hansen later studied at Mark Hopkins Institute under Arthur Mathews (1903-06), followed by two years in Stuttgart, Germany at the Royal Academy under Carlos Grethe. After visiting the art centers of Paris, Munich, Holland, and Belgium, Hansen signed on as deckhand to a Norwegian steam trawler, the first of many boats which he would crew during the next four years.

Upon returning to San Francisco in 1912, he taught at UC Berkeley and the California School of Fine Arts. He settled in Monterey in 1913 and taught private classes and was instrumental in forming the Carmel Art Institute.

Hansen maintained a studio-home at 716 Pacific Street until building a home next door to artist Julian Greenwell on El Dorado Street. He lived there until his death on April 23, 1957.