1. capable of being used by humans for water-borne transportation 2. legal (a) interstate waters, intrastate lakes, rivers, and streams which are utilized by interstate travelers for recreational or other purposes; (b) intrastate lakes, rivers, and streams from which fish or shellfish are taken and sold in interstate commerce; and (c) intrastate lakes, rivers, and streams that are utilized for industrial purposes by industries in interstate commerceThis definition last updated 07/21/2008