Treanor produced his sand murals by sketching designs on paper before using a rake to recreate the design on a beach. The work would then remain on the beach until washed away by the tide. As a result of their innately fleeting nature and circular forms, Treanor's sand murals have been compared to crop circles.
Marc had a son and a daughter and had begun doing sand art to entertain them at the beach. This turned in to a career once he moved to Wales, working with a variety of organisations and charities throughout Wales.