(a) Whenever it comes to the attention of the District Commander that a safety zone and regulations may be required concerning any OCS facility being constructed, maintained, or operated on the Outer Continental Shelf or its appurtenances and attending vessels, or the adjacent waters, the District Commander may initiate appropriate inquiry to determine whether a safety zone and regulations should be established. In making this determination, the District Commander considers all relevant safety factors, including existing or reasonably foreseeable congestion of vessels, the presence of unusually harmful or hazardous substances, and any obstructions within 500 meters of the OCS facility. If the District Commander determines that the circumstances warrant the establishment of a safety zone and regulations the District Commander takes action as necessary consistent with the provisions of this part.

(b) Except as provided in paragraph (c) of this section, a safety zone and necessary regulations may be established concerning any OCS facility being constructed, maintained or operated on the Outer Continental Shelf, following publication of a notice of proposed rule making in the Federal Register and after interested parties have been given the opportunity to submit comments. A zone and necessary regulations may be in effect during any period when construction equipment and materials are within 500 meters of the construction site until the removal of all portions of the facility.

(c) A safety zone and necessary regulations may be established without public rule making procedures when the District Commander determined that imminent danger exists with respect to the safety of life and property on an OCS facility constructed, maintained, or operated on the Outer Continental Shelf, its appurtenances and attending vessels or adjacent waters. A safety zone and regulations may be made effective on the date the rule is published in the Federal Register. However, if circumstances require, they may be placed into effect immediately, followed promptly by publication in the Federal Register. The District Commander may utilize, in addition to broadcast Notices to Mariners, Local Notices to Mariners, and Notices to Mariners, newspapers, and broadcasting stations to disseminate information concerning a safety zone and regulations pertaining thereto. The public may comment concerning the establishment of a safety zone or regulations under this paragraph. A safety zone or regulations may be modified or withdrawn, as appropriate, based on the comments received.

(d) Geographic coordinates expressed in terms of latitude or longitude, or both, are not intended for plotting on maps or charts whose referenced horizontal datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts reference to NAD 83 only after application of the appropriate corrections that are published on the particular map or chart being used.