Appeared in Popular Mechanics Magazine, September 1924 (page #362).
Photo credit: unknown.
"For those who enjoy the sport of surf riding, a pneumatic board that is inflated with a hand pump has been placed on the market. It is constructed of a durable, rubberized fabric and has ribs which hold it flat for riding on the surface. It will support the weight of a heavy person. When deflated, it folds up into a small bundle weighing about six pounds, and is four feet eight inches long and twenty inches wide when blown up. It is said to be safer for the rider and other bathers than those of wood and cork. Bright-colored designs give the new boards a festive touch."
Retrievable on Google Books online: where, in addition to the magazine text, someone was inspired enough to write names, patent numbers and addresses in pencil in the margins of their copy.
The apparent difference in chamber configuration is interesting.