U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 9457493 PUBLICATION DATE: 12/30/2014 Name: SW TERROR BAY AK NOAA Chart: 16597 Latitude: 57° 44.6' N ( 57.74403) USGS Quad: KODIAK (c-4), ALASKA Longitude: 153° 11.7' W (-153.19547) To reach the tidal bench marks from Port Lions, AK by boat, start at the entrance to Settler Cove at position 57 52.64 N, 152 50.18 W, and proceed in Kizhuyak Bay on course 050 T for 2.5 nautical miles (NM) to 57 54.26 N, 152 46.55 W, then proceed through Whale Passage on course 312 T for 3.0NM to 57 56.24 N, 152 50.74 W, where Pokati Point will be abeam to port. Continue through Kupreanof Strait on course 291 T for 15.5NM to 58 01.77 N, 153 18.13 W with Outlet Cape abeam to port, then turn to port to course 200 T for 4.9NM, exiting Kupreanof Strait, entering Viekoda Bay, to 57 57.17 N, 153 21.35 W. Alter course to 130 T for 3.4NM to position 57 54.95 N, 153 16.40 W and then proceed on course 155 T entering East Uginik Passage for 5.1NM to position 57 50.37 N, 153 12.31 W. Alter to course 172 T for 2.0NM to continue through East Uginik Passage. Continue south on course 180 T for 2.5NM past the entrance to Uganik Passage and in to Terror Bay. Finally, proceed on course 198 T for 2.3NM to the end of Terror Bay where the benchmarks are located along the rocky shore T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 7493 C 2014 DESIGNATION: 945 7493 C MONUMENTATION: Bench Mark disk VM#: 21295 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: Bedrock outcrop OPUS PID#: BBDR11 LATITUDE: 57° 43.9' N ( 57.73167) LONGITUDE: 153° 13.4' W (-153.22306) The primary bench mark is a disk set flush in bedrock 3m (9.9ft) in front of an 8m (26.3ft) vertical face. However, direct line of sight is blocked by a bedrock outcrop directly N. When on the mark, the highest point on the E shore 2410ft peak charted at 57 44.55 N, 153 10.17 W bears 088 T (072 M).
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 9457493 PUBLICATION DATE: 12/30/2014 Name: SW TERROR BAY AK NOAA Chart: 16597 Latitude: 57° 44.6' N ( 57.74403) USGS Quad: KODIAK (c-4), ALASKA Longitude: 153° 11.7' W (-153.19547) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7493 A 2014 DESIGNATION: 945 7493 A MONUMENTATION: Bench Mark disk VM#: 21293 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: Bedrock outcrop OPUS PID: LATITUDE: 57° 43.9' N ( 57.73111) LONGITUDE: 153° 13.4' W (-153.22306) The bench mark is a disk set vertically in the middle of series jagged bedrock outcroppings facing 026 T (010 M) at the 2823ft peak located at 57 49.81 N, 153 06.62 W, S of the small stream bisecting a small rocky beach (charted on 16597 as the northernmost stream on the west bank of Terror Bay). BENCH MARK STAMPING: 7493 B 2014 DESIGNATION: 945 7493 B MONUMENTATION: Bench Mark disk VM#: 21294 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: Bedrock outcrop OPUS PID: LATITUDE: 57° 43.9' N ( 57.73167) LONGITUDE: 153° 13.4' W (-153.22333) The bench mark is a disk set flush in bedrock 4m (13.1 ft) in front of a 16m (52.5 ft) vertical face, N of the small stream bisecting a small rocky beach (charted on 16597 as the N most stream on the W bank of Terror Bay). However direct line of sight is blocked by a bedrock outcropping.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 9457493 PUBLICATION DATE: 12/30/2014 Name: SW TERROR BAY AK NOAA Chart: 16597 Latitude: 57° 44.6' N ( 57.74403) USGS Quad: KODIAK (c-4), ALASKA Longitude: 153° 11.7' W (-153.19547) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7493 D 2014 DESIGNATION: 945 7493 D MONUMENTATION: Bench Mark disk VM#: 21296 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: Bedrock outcrop OPUS PID: LATITUDE: 57° 43.9' N ( 57.73194) LONGITUDE: 153° 13.4' W (-153.22306) The bench mark is a disk set flush in bedrock outcropping. Vegetation is low on the rock face behind 945 7493 D. When on the mark, the highest point on the E shore 2410ft peak charted at 57 44.55 N, 153 10.17 W bears 088 T (072 M). The prominent point on the W shore of Terror Bay towards the mudflats bears 150 T (134 M). The 2823ft peak charted at 57 49.82 N, 153 06.81 W bears 048 T (032 M) BENCH MARK STAMPING: 7493 E 2014 DESIGNATION: 945 7493 E MONUMENTATION: Bench Mark disk VM#: 21297 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: Bedrock outcrop OPUS PID: LATITUDE: 57° 43.9' N ( 57.73222) LONGITUDE: 153° 13.4' W (-153.22278) The bench mark is a disk set flush in bedrock 3m (9.9ft) in front of an 8m (26.3ft) vertical face. When on the mark, the highest point on the E shore 2410ft peak charted at 57 44.55 N, 153 10.17 W bears 088 T (072 M). The prominent point on the W shore of Terror Bay towards the mudflats bears 154 T (138 M).
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 9457493 PUBLICATION DATE: 12/30/2014 Name: SW TERROR BAY AK NOAA Chart: 16597 Latitude: 57° 44.6' N ( 57.74403) USGS Quad: KODIAK (c-4), ALASKA Longitude: 153° 11.7' W (-153.19547) T I D A L D A T U M S Tidal datums at SW TERROR BAY based on: LENGTH OF SERIES: 1 MONTH TIME PERIOD: September 2014 - September 2014 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9457804 ALITAK, LAZY BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 4.313 MEAN HIGH WATER MHW = 4.038 MEAN TIDE LEVEL MTL = 2.270 MEAN SEA LEVEL MSL = 2.253 MEAN LOW WATER MLW = 0.503 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 7493 C 2014 3.926 -0.112 7493 A 2014 5.335 1.297 7493 B 2014 4.688 0.650 7493 D 2014 4.514 0.476 7493 E 2014 4.527 0.489
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 9457493 PUBLICATION DATE: 12/30/2014 Name: SW TERROR BAY AK NOAA Chart: 16597 Latitude: 57° 44.6' N ( 57.74403) USGS Quad: KODIAK (c-4), ALASKA Longitude: 153° 11.7' W (-153.19547) D E F I N I T I O N S Mean Sea Level (MSL) is a tidal datum determined over a 19-year National Tidal Datum Epoch. It pertains to local mean sea level and should not be confused with the fixed datums of North American Vertical Datum of 1988 (NAVD88). NAVD88 is a fixed datum derived from a simultaneous, least squares, minimum constraint adjustment of Canadian/Mexican/United States leveling observations. Local mean sea level observed at Father Point/Rimouski, Canada was held fixed as the single initial constraint. NAVD88 replaces NGVD29 as the national standard geodetic reference for heights. Bench mark elevations relative to NAVD88 are available from NGS through the World Wide Web at National Geodetic Survey. NGVD29 is a fixed datum adopted as a national standard geodetic reference for heights but is now considered superseded. NGVD29 is sometimes referred to as Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological Survey Topographic Quads. NGVD29 was originally derived from a general adjustment of the first-order leveling networks of the U.S. and Canada after holding mean sea level observed at 26 long term tide stations as fixed. Numerous local and wide-spread adjustments have been made since establishment in 1929. Bench mark elevations relative to NGVD29 are available from the National Geodetic Survey (NGS) data base via the World Wide Web at National Geodetic Survey. NAVD88 and NGVD29 are fixed geodetic datums whose elevation relationships to local MSL and other tidal datums may not be consistent from one location to another. The Vertical Mark Number (VM#) and PID# shown on the bench mark sheet are unique identifiers for bench marks in the tidal and geodetic databases, respectively. Each bench mark in either database has a single, unique VM# and/or PID# assigned. Where both VM# and PID# are indicated, both tidal and geodetic elevations are available for the bench mark listed. The NGS's Integrated Data Base (IDB PID) provides geodetic datum based on traditionally leveled and bluebooked ties to the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/. The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/. The NAVD88 elevation is shown on the Elevations of Tidal Datums Table Referred to MLLW only when two or more of the bench marks listed have NAVD88 elevations. The NAVD88 elevation relationship shown in the table is derived from an average of several bench mark elevations relative to tide station datum. As a result of this averaging, NAVD88 bench mark elevations computed indirectly from the tidal datums elevation table may differ slightly from NAVD88 elevations listed for each bench mark in the NGS database.