Water Bellies on Water Bicycles These charming girls on water bicycles cause something of a sensation at Coney Island , when they engaged in a race with men swimmers and won easily . The machines are sustained in the water by tanks , the head and shoulders of the riders being above water 10 May 1921 , Water Bellies on Water Bicycles These charming girls on water bicycles cause something of a sensation at Coney Island , when they engaged in a race with men swimmers and won easily . The machines are sustained in the water by tanks , the head and shoulders of the riders being above water 10 May 1921