Section 150.905 - Why are safety zones, no anchoring areas, and areas to be avoided established?(a) Safety zones, no anchoring areas (NAAs) and areas to be avoided (ATBAs) under this subchapter are established to promote safety of life and property, marine environmental protection, and navigational safety at deepwater ports and adjacent waters.(b) Safety zones are the only federally regulated navigation areas. They accomplish these objectives by preventing or controlling specific activities, limiting access by vessels or persons, and by protecting the living resources of the sea from harmful agents.(c) The NAAs and ATBAs are established via the International Maritime Organization (IMO). An NAA, specifically established to protect vessels in transit and sub-surface deepwater port components, will be mandatory. An ATBA will be a recommendatory routing measure.(d) The sizes of restricted areas will be the minimum size needed to ensure safety, while at the same time considering potential impacts on other activities, including recreational boating, fishing, and Outer Continental Shelf activity.USCG-1998-3884, 71 FR 57651, Sept. 29, 2006, as amended by USCG-2013-0397, 78 FR 39183, July 1, 2013