Ah... now we're talking. Diving into Leslie's costume history archives. 7 high resolution images from fashion magazines of the late teens and early 1920s (and those magazine were huge, so these are quite large: most are 8" x 12" at 300 dpi!). Related collage sheets are below, but these are perfect for resizing to fit your vintage beachy project.
Set of 7.dgtlUSG art deco costumes bathing beauties fashion umbrella parasol hat