Plenty of surfers embraced Tom Blake’s hollow boards as wave riding tools, both in Hawaii and on the U.S. mainland. But Blake was not finished tinkering when he earned his first patent in 1932 and his contributions to surfboard innovation continued throughout the decade. Even as he licensed out his hollow board designs to firms like the Thomas Rogers Company, the Robert Mitchell Manufacturing Company, the Los Angeles Ladder Company and the Catalina Equipment Company, Blake came up with a series of boards in various sizes and shapes for racing, lifeguard rescue boards and, of course, for surfing.

In general, the surfboards could be distinguished from the paddleboards by their wide square tails. They ranged in size from 10 to 14 feet and weighed mostly around 45 to 55 pounds. Some of them, like the one displayed here, customized with the inscription “Nalu”—Hawaiian for “wave”—featured a semi-rounded rail that would have made it somewhat easier to turn and more forgiving of minor lapses in balance by the surfer. It’s interesting that Blake was also the first person to use a stabilizing fin on a surfboard, an innovation that would make a huge difference in making boards more maneuverable. But despite his 1935 introduction of the idea and offering a fin as an option on both factory-produced boards and in the do-it-yourself kits that were available, fins didn’t catch on with most surfers until the years following WW II.

All of Blake’s hollow boards featured what at first glance might look like a metal badge or emblem with the maker’s company name. In fact, this feature is the seat of a screw-in brass plug, because no matter how well-made and maintained with varnish, the hollow boards were notoriously leaky and had to be taken ashore to be drained after every 20 or 30 minutes of use.