Section 27.100 - Applicability; preemptive effect(a) You must comply with this part if your towing vessel operates on the navigable waters of the United States, unless your vessel is one exempt under paragraph (b) of this section.(b) This part does not apply to you if your towing vessel is-(1) Used solely for any of the following services or any combination of these services-(i) Within a limited geographic area, such as a fleeting-area for barges or a commercial facility, and used for restricted service, such as making up or breaking up larger tows;(iii) For assistance towing as defined by 46 CFR 10.103 ;(iv) For response to emergency or pollution;(2) A public vessel that is both owned, or demise chartered, and operated by the United States Government or by a government of a foreign country; and that is not engaged in commercial service;(3) A foreign vessel engaged in innocent passage; or(4) Exempted by the Captain of the Port (COTP).(c) If you think your towing vessel should be exempt from these requirements for a specified route, you should submit a written request to the appropriate COTP. The COTP will provide you with a written response granting or denying your request. The COTP will consider the extent to which unsafe conditions would result if your vessel lost propulsion because of a fire in the engine room.(d) You must test and maintain all of the equipment required by this part in accordance with the attached nameplate or manufacturer's approved design manual.(e) The regulations in this part have preemptive effect over State or local regulations in the same field.USCG-2000-6931, 69 FR 34069, June 18, 2004, as amended by USCG-2006-24797, 77 FR 33871, June 7, 2012