Traditional International Maritime Signal Flags are used as a means of ship to ship communication. On dry land, the nautical flag and pennant aesthetic is less about sending messages like "diver down" or "carrying/discharging dangerous goods" and more about sending messages about the wearer's affiliation with a life of genteel leisure and good taste, which actually would include a familiarity of what maritime signal flags are for.
If a size is not listed, it is sold out.
Model measurements are 6'1, 150 lbs. Model is wearing a size S.