Section 720, acts June 17, 1910, ch. 301, 7, 36 Stat. 538; Mar. 4, 1913, ch. 141, 1, 37 Stat. 736, related to general control by Commandant of Coast Guard. See section 81 of Title 14, Coast Guard. Section 720a, act Aug. 16, 1937, ch. 665, 3, 50 Stat. 667, related to establishment and maintenance of aids to navigation in certain waters. See section 81 of Title 14, Coast Guard.