Amendment required all tank vessels, of at least 10,000 gross tons, that carry oil or hazardous substances in U.S. waters to be equipped with double hulls. \ As amended by the Torricelli amendment (A024), all tank vessels of at least 20,000 deadweight tons, that carry oil or hazardous substances in U.S. waters were required to be equipped with double bottoms. \ As amended by the Gunderson amendment (A026), language limiting the requirement for double hulls to vessels of at least 10,000 gross tons was deleted so as to place barges on inland waterways under the requirement.