Circumference = 40 ft.
Above is a drawing of the SPIRAL® h20 patented geotube. The structure has an outside armor with the patented "Helical Ribs".

The two inner bladders are independent of each other and dissipate any wave energy. The outside "Helical Ribs" hold the two inner tubes together and will not allow one to go over the other.
This SPIRAL® h20 geotube is holding back 15' of water.
SPIRAL® h20 geotube
Filled With Water
Filled With Water
BRADLEY INDUSTRIAL TEXTILES INC.
Since 1977, BRADLEY has stood for Quality, Innovation
and Cost Effective Solutions in Geotextiles.
Water Height = 6 ft
H = 8 ft