David G. Thomas has been a swimming teacher and coach since 1948, when he became a water safety field representative for the American National Red Cross. In 1955 he became swimming coach and director of aquatics at Berea High School, Berea, OH. Eight years later he moved to the State University of New York at Binghamton, where he was director of aquatics and swimming coach until retiring as professor emeritus in 1985.
Thomas gained nationwide prominence in 1972 by producing a textbook, a teaching guide, exams, and visual aids for training swimming pool operators. The Swimming Pool Operators Handbook and the other materials were published by the National Swimming Pool Foundation as the basis for their Certified Pool Operators program.
Thomas has published many articles on aquatic subjects and is a contributing author to several books on swimming pool design and operation. He has written extensively since retirement, including the Leisure Press books Swimming: Steps to Success, Teaching Swimming: Steps to Success, Professional Aquatic Management (coauthored with Robert Clayton), and Competitive Swimming Management. Self-employed as a consultant in aquatics and pool design and operation, Thomas lives with his wife, Virginia, in Anderson, SC, where he enjoys swimming for fitness and boating.