It is unlawful for the master or any person in charge of any vessel of any kind lying at any dock or while navigating in the harbor, to cause any whistle, siren, foghorn, bell, or any other kind of sound producing apparatus to be blown or sounded for any purpose other than required by law or by the U.S. Coast Guard “Rules of the Road: International - Inland” Commandant Instruction M16672.2 series. These rules are hereby made a part of this Title. Copies are available at Group Portland, United States Coast Guard. No such apparatus shall be tested or adjusted within the port without written permission of the Harbor Master. However, boilers and tanks may be blown out through an underwater exhaust between the hours of7 a.m. and 10 p.m. of any day. This section shall not prevent the routine testing of any sound producing apparatus in connection with actual getting under way.