NOAA ENCŪ

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

US4AK7LP - ALASKA


INDEX:

NOTE A
SUPPLEMENTAL INFORMATION
AIDS TO NAVIGATION
CAUTION - TEMPORARY CHANGES
CAUTION - SUBMARINE PIPELINES AND CABLES
WARNING - PRUDENT MARINER
POLLUTION REPORTS
AUTHORITIES
MINERAL DEVELOPMENT STRUCTURES
CAUTION - MARINERS
COLREGS, 80.1705
SUBSISTENCE WHALING IN THE BEAUFORT SEA
CAUTION - DEPTHS
WATER LEVELS, CURRENTS, AND TIDES
COMMENTS REQUESTED
RADAR REFLECTORS 
ADDITIONAL INFORMATION
CAUTION - QUALITY OF BATHYMETRIC DATA
CAUTION - USE OF RADIO SIGNALS (LIMITATIONS)
HORIZONTAL DATUM


NOTES:

NOTE A
Navigation regulations are published in Chapter 2, U.S. Coast Pilot 9. Additions or revisions to Chapter 2 are published in the Notice to Mariners. Information concerning the regulations may be obtained at the Office of the Commander, 17th Coast Guard District in Juneau, Alaska, or at the Office of the District Engineer, Corps of Engineers in Anchorage, Alaska.
Refer to charted regulation section numbers.


SUPPLEMENTAL INFORMATION
Consult U.S. Coast Pilot 9 for important supplemental information.


AIDS TO NAVIGATION
Consult U.S. Coast Guard Light List for supplemental information concerning aids to navigation.


CAUTION - TEMPORARY CHANGES
Temporary changes or defects in aids to navigation are not indicated. See Local Notice to Mariners.


CAUTION - SUBMARINE PIPELINES AND CABLES
Additional uncharted submarine pipelines and submarine cables may exist within the area of this chart. Not all submarine pipelines and submarine cables are required to be buried, and those that were originally buried may have become exposed.  Mariners should use extreme caution when operating vessels in depths of water comparable to their draft in areas where pipelines and cables may exist, and when anchoring, dragging or trawling. Covered wells may be marked by lighted or unlighted buoys.


WARNING - PRUDENT MARINER
The prudent mariner will not rely solely on any single aid to navigation, particularly on floating aids. See U.S. Coast Guard Light List and U.S. Coast Pilot for details.


POLLUTION REPORTS
Report all spills of oil and hazardous substances to the National Response Center via 1-800-424-8802 (toll free), or to the nearest U.S. Coast Guard facility if telephone communication is impossible (33 CFR 153).


AUTHORITIES
Hydrography (from surveys of 1951-53) and topography by the National Ocean Service, Coast Survey, with additional data from the State of Alaska, Geological Survey, and U.S. Coast Guard.


MINERAL DEVELOPMENT STRUCTURES
Obstruction lights and sound (fog) signals are required for fixed mineral development structures, subject to approval by the District Commander, U.S. Coast Guard (33 CFR 67).


CAUTION - MARINERS
Mariners are advised that in the shallow waters of the Beaufort Sea, water levels are strongly influenced by meteorological conditions. Strong offshore winds can produce water depths up to 0.8 meters (2.6 feet) feet less than those shown.


COLREGS, 80.1705
International Regulations for Preventing Collisions of Sea, 1972. The entire area of this chart falls seaward of the COLREGS Demarcation Line. 


SUBSISTENCE WHALING IN THE BEAUFORT SEA
Mariners should be aware that Alaskan Natives engage in subsistence whaling in the Beaufort Sea from August 15 to October 31.  Vessel operators are requested to contact the Alaska Eskimo Whaling Commission at (907) 852-2392, or aewcdir@barrow.com prior to entering this area for information about the location and avoidance of traditional Native hunting parties.


CAUTION - DEPTHS
Depths may vary as much as 1.8 meters (6 feet) due to iceberg groundings.


WATER LEVELS, CURRENTS, AND TIDES
Real-time water levels, tide predictions, and tidal current predictions are available on the internet from NOAA's Center for Operational Oceanographic Products and Services (CO-OPS) at https://tidesandcurrents.noaa.gov/water_level_info.html and https://tidesandcurrents.noaa.gov/currents_info.html.


COMMENTS REQUESTED
NOAA encourages users to submit inquiries, discrepancies, or comments about this chart via NOAA's ASSIST tool at https://www.nauticalcharts.noaa.gov/customer-service/assist/.


RADAR REFLECTORS 
Radar reflectors have been placed on many floating aids to navigation. Individual radar reflector identification on these aids has been omitted from this chart.


ADDITIONAL INFORMATION
Additional information can be obtained at www.nauticalcharts.noaa.gov.


CAUTION - QUALITY OF BATHYMETRIC DATA
The areas represented by the object M_QUAL (Quality of data) are approximate due to generalizing for clarity. Caution is advised, particularly for nearshore navigation or voyage planning. M_QUAL represents areas of uniform quality of bathymetric data. The CATZOC (Category of zone of confidence in data) attribute of M_QUAL provides an assessment of the overall zone of confidence.


CAUTION - USE OF RADIO SIGNALS (LIMITATIONS)
Limitations on the use of radio signals as aids to marine navigation can be found in the U.S. Coast Guard Light Lists and National Geospatial-Intelligence Agency Publication 117. Radio direction-finder bearings to commercial broadcasting stations are subject to error and should be used with caution.


HORIZONTAL DATUM 
The NOAA ENC references the World Geodetic System of 1984 (WGS-84). For charting purposes, the horizontal control of the current realization of WGS-84 is functionally equivalent to the International Terrestrial Reference Frame 2020 (ITRF2020) at the meter level for charts at scales of 1:5,000 or smaller.


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