Christman studied at the National Academy of Fine Art, New York, with Daniel Greene; and the Art Students League, New York, with Robert Brackman and Everett R. Kinstler. His work has been exhibited in many venues, including the Salmagundi Club of New York where he was awarded the Club Prize in 1971.

Christman is a member of the American Society of Marine Artists. A resident of Vero Beach, his paintings of the Indian River and local seascapes are widely collected.