Awaiting the Swell
Boy, surfing attire sure has changed since the 14th century.
First thing that came to mind when I saw this image, depicting a line with bowmen waiting for engagement at the battle of Crécy, in 1346, was how it resembled surfers relaxing on the beach. I also like how the guy in the white armor in the foreground seems to be giving our foreground "surfer' some tips. Dude, you've got a boogie board at your feet, along with a single ski. I don't think you're qualified to tell anyone how to do anything.
The 'surfboards' you see in the pic are bow cases, usually made from oiled leather, meant to keep your bow and bowstring protected from the elements. This was especially important in the sea-sprayed coastal areas in France and Britain where many battles took place, as too much exposure to moisture will warp and weaken wood.
If anyone is interested, I had seen this image a few places before, but I snagged it from Beyond the Black Gate. Go read the blog. It's good, especially if you are interested in older editions of D&D and the sword and planet genre.