Abstract: Provided are an aqueous composition with which the surface of stainless steel is adequately roughened in an efficient manner with few steps, a method for roughening stainless steel, etc. The problem mentioned above is solved by an aqueous composition for roughening the surface of stainless steel, the aqueous composition including 0.1-20 mass % of hydrogen peroxide with reference to the total amount of the aqueous composition, 0.25-40 mass % of copper ions with reference to the total amount of the aqueous composition, and 1-30 mass % of halide ions with reference to the total amount of the aqueous composition.

Abstract: A freeze resistant buoy system includes a tail-tube buoy having a thermally insulated section disposed predominantly above a waterline, and a thermo-siphon disposed predominantly below the waterline.