NOAA ENCŪ NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION US4AK7MH - ALASKA INDEX: NOTE A AUTHORITIES AIDS TO NAVIGATION WARNING - PRUDENT MARINER POLLUTION REPORTS SUPPLEMENTAL INFORMATION CAUTION - DEPTHS RACON COLREGS, 80.1705 WATER LEVELS, CURRENTS, AND TIDES CAUTION - USE OF RADIO SIGNALS (LIMITATIONS) CAUTION - SUBMARINE PIPELINES AND CABLES CAUTION - TEMPORARY CHANGES ADDITIONAL INFORMATION COMMENTS REQUESTED RADAR REFLECTORS CAUTION - QUALITY OF BATHYMETRIC DATA 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. AUTHORITIES Hydrography (From surveys of 1952-53) and topography by the National Ocean Service, Coast Survey, with additional data from the State of Alaska, the Geological Survey, and U.S. Coast Guard. AIDS TO NAVIGATION Consult U.S. Coast Guard Light List for supplemental information concerning aids to navigation. 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). SUPPLEMENTAL INFORMATION Consult U.S. Coast Pilot 9 for important supplemental information. CAUTION - DEPTHS Depths may vary as much as 1.8 meters (6 feet) due to iceberg groundings. RACON Radar Transponder Beacons or RACONS are activated by radars operating on the X-Band frequencies 9300 to 9450 MHz and when activated will emit an international morse code character which will be visible on the radar screen that activated the RACON. The effective range of the RACONS will be from 11 to 27 nautical miles. The RACONS will be maintained seasonally from 1 July to 15 September. COLREGS, 80.1705 International Regulations for Preventing Collisions at Sea, 1972. The entire area of this chart falls seaward of the COLREGS Demarcation Line. 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. 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. 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. CAUTION - TEMPORARY CHANGES Temporary changes or defects in aids to navigation are not indicated. See Local Notice to Mariners. ADDITIONAL INFORMATION Additional information can be obtained at www.nauticalcharts.noaa.gov. 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. 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. 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. END OF FILE