While out at a venue that encourages dancing (ie, the bar) you will often see Kelp Girls in segregated groups. Their choices in footwear, and sometimes clothing, make movement difficult. Their shoes inhibit movement, and thus, while looking out into a crowded dance floor, you will see women swaying and wiggling to the music without their feet ever shifting from their inital position. The effect is that of kelp and other seaweed, moving in the currents of the water.
Did you see that "Kelp Girl"? Her stilettos must have been 5 inches high.