All watercraft carrying cargoes of oil or any other highly inflammable material, while lying at any dock or at anchor, shall have at all times two fire resistant cable tow lines, one from the bow and one from the stern, of a size appropriate for towing the watercraft with an eye on each end, located on the offshore side, not more than four feet above the water. [Ord. 9515, 1985; Ord. 8655 § 2(N), 1978].