This postcard from Hawaii is most likely from the mid-1930s, when there was a transition from the wool tank suits of the early 20th century to surfing topless. Up until around 1936 it was considered improper and even illegal for men to bare their chests in public. Johnny Weissmuller wearing a loin cloth in Tarzan began to change that, but the change was gradual. So that’s that, but what is that structure behind the wave? Most likely the pier jutting out from the Moana Hotel.