[4] Drawing inspiration from The Moon and Sixpence, Somerset Maugham's novel based on the life of the painter Paul Gauguin, Etnier pursued painting, launching his career with a solo exhibition at Dudensing Galleries, New York City in 1931.
His work shows street scenes in his home state of Pennsylvania, waterfronts from his travels to Haiti and the Bahamas, (and made while sailing the Eastern Seaboard aboard his 70-foot sailboat, Morgana), aerial perspectives created as he learned to fly, and dramatic Maine landscapes, painted while he renovated a stately 1862 home, "Gilbert Head".
[4][8] In 1938 he executed the mural "Waiting for the Mail," installed at the U.S. Post Office in Spring Valley, New York, and listed on the National Register of Historic Places in 1988.
In May 1942, Etnier was commissioned as a lieutenant and assigned as commanding officer of the USS Mizpah, a North Atlantic convoy escort ship.
[4][12] Etnier purchased land in South Harpswell, Maine in 1948 to build "Old Cove", his dream house and studio.
Named for the private cove it overlooked, the home served as the foundation for a productive and increasingly serene period in Etnier's career.
Although still traveling south most winters in his boat, his life took a more domestic turn as he re-adopted Maine as his permanent home and married his fourth wife, Samuella "Brownie" Brown Rose.
During those years, he painted daily, exhibited widely and enjoyed popular support, artistic awards and media attention.
Etnier's work became more architectural, marked by stark geometry, light and shadow, impressionistic figures and accents of color and modern culture.
He adopted an artist's discipline of rising early and painting each morning (learned first from Rockwell Kent), seeking to capture the essence of Maine waterfronts and landscapes and the effects of light.
Acclaim includes his election as an academician by the National Academy of Design and a retrospective exhibit at the Farnsworth Museum in Rockland, Maine in 1953;[13] receipt of the Saltus Award by the National Academy of Design in 1955; a solo exhibition at York Junior College in York, Pennsylvania and the Samuel F. B. Morse gold medal from the National Academy of Design in 1964; and a solo exhibition at the Bristol Art Museum in Bristol, Rhode Island in 1965.