Section 147, act Oct. 11, 1951, ch. 495, 6, Pt. D, 65 Stat. 419, related to sound signals of vessels indicating course. Section 147a, act Oct. 11, 1951, ch. 495, 6, Pt. D, 65 Stat. 419, related to additional precautions. Section 147b, act Oct. 11, 1951, ch. 495, 6, Pt. D, 65 Stat. 420, related to local rules for harbors and inland waters. Section 147c, act Oct. 11, 1951, ch. 495, 6, Pt. D, 65 Stat. 420, related to distress signals. Section 147d, act Oct. 11, 1951, ch. 495, 6, Pt. D, 65 Stat. 420, related to orders to helmsmen, and has been omitted.