U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 7 Station ID: 9451287 PUBLICATION DATE: 11/13/2003 Name: BEECHER PASS, WRANGELL NARROWS AK NOAA Chart: 17375 Latitude: 56° 35.7' N ( 56.59500) USGS Quad: PETERSBURG (C-3) Longitude: 132° 59.2' W (-132.98700) To reach the tidal bench marks from the Petersburg, Alaska, South Harbor public boat launch, proceed 16.0 km (8.7 nm) south down Wrangell Narrows past Papke's Landing state warf, continue 4.6 km (2.5 nm) south past Anchor Point, The tide gauge was located on the NE tip of Inlet Point on the southern shore of Beecher Pass at its confluence with Wrangell Narrows. The tidal bench mark are located on the beach. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: NO 4 1929 DESIGNATION: 945 1287 TIDAL 4 MONUMENTATION: Tidal Station disk VM#: 17241 AGENCY: US Coast & Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Rock ledge OPUS PID: LATITUDE: 56° 35.7' N ( 56.59500) LONGITUDE: 132° 59.3' W (-132.98800) The bench mark is a disk set in rock ledge 13.84 m (45.4 ft) SSE of bench mark USE 54-89 1989, 14 m (45 ft) east of bench mark 945 1287 TIDAL 3, 13.17 m (43.2 ft) SW from bench mark 945 1287 TIDAL 1, and 7 m (23 ft) east of bench mark NO 5 1929.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 7 Station ID: 9451287 PUBLICATION DATE: 11/13/2003 Name: BEECHER PASS, WRANGELL NARROWS AK NOAA Chart: 17375 Latitude: 56° 35.7' N ( 56.59500) USGS Quad: PETERSBURG (C-3) Longitude: 132° 59.2' W (-132.98700) T I D A L B E N C H M A R K S BENCH MARK STAMPING: DESIGNATION: 945 1287 TIDAL 1 ALIAS: BM 1 MONUMENTATION: Bolt VM#: 17239 AGENCY: US Coast & Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Boulder OPUS PID: LATITUDE: 56° 35.7' N ( 56.59500) LONGITUDE: 132° 59.3' W (-132.98800) The bench mark is a copper bolt set in top of rock below apparent high water line, south of cobble beach at Inlet Point on west bank of Wrangell Narrows, 18 m (60 ft) NW from bench mark 945 1287 TIDAL 3, 13.17 m (43.2 ft) NE of bench mark NO 4 1929, 12.13 m (39.8 ft) east of bench mark NO 5 1929, 11 m (36 ft) east of bench mark USE 54-89 1989, and 3 m (10 ft) from an arrow cut into red granite boulder.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 7 Station ID: 9451287 PUBLICATION DATE: 11/13/2003 Name: BEECHER PASS, WRANGELL NARROWS AK NOAA Chart: 17375 Latitude: 56° 35.7' N ( 56.59500) USGS Quad: PETERSBURG (C-3) Longitude: 132° 59.2' W (-132.98700) T I D A L B E N C H M A R K S BENCH MARK STAMPING: DESIGNATION: 945 1287 TIDAL 3 ALIAS: BM 3 MONUMENTATION: Drill Hole VM#: 17240 AGENCY: US Coast & Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Rock ledge OPUS PID: LATITUDE: 56° 35.7' N ( 56.59500) LONGITUDE: 132° 59.3' W (-132.98800) The bench mark is a 3/4 inch drill hole with three chiseled radial lines cut in level shelf on a prominent ledge, 22 m (73 ft) SE of bench mark USE 54-89 1989, and 18 m (60 ft) SE from bench mark 945 1287 TIDAL 1. BENCH MARK STAMPING: NO 5 1929 DESIGNATION: 945 1287 TIDAL 5 MONUMENTATION: Tidal Station disk VM#: 17242 AGENCY: US Coast & Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Rock ledge OPUS PID: LATITUDE: 56° 35.7' N ( 56.59500) LONGITUDE: 132° 59.3' W (-132.98800) The bench mark is a disk set on a ledge, 12.13 m (39.8 ft) west of bench mark 945 1287 TIDAL 1, on the same ledge as and 7.50 m (24.6 ft) SW of bench mark USE 54-89 1989 and inside of it, 7.50 m (24.6 ft) SW of bench mark NO 4 1929, and 4 m (14ft) in front of a vertical cliff.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 7 Station ID: 9451287 PUBLICATION DATE: 11/13/2003 Name: BEECHER PASS, WRANGELL NARROWS AK NOAA Chart: 17375 Latitude: 56° 35.7' N ( 56.59500) USGS Quad: PETERSBURG (C-3) Longitude: 132° 59.2' W (-132.98700) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1287 A 2003 DESIGNATION: 945 1287 A MONUMENTATION: Tidal Station disk VM#: 17243 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Granite boulder OPUS PID: LATITUDE: 56° 35.7' N ( 56.59500) LONGITUDE: 132° 59.3' W (-132.98800) The bench mark is a disk set in top of 1 m x 1m x 0.27 m (4 ft x 4 ft x 0.9 ft) high granite boulder firmly rooted at apparent high water line immediately SE of Inlet Point, and 11m (35 ft) north of bench mark 1287 B 2003. BENCH MARK STAMPING: 1287 B 2003 DESIGNATION: 945 1287 B MONUMENTATION: Tidal Station disk VM#: 17244 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Granite boulder OPUS PID: LATITUDE: 56° 35.7' N ( 56.59500) LONGITUDE: 132° 59.3' W (-132.98800) The bench mark is a disk set in the center of bottom of two overlapping flat granite slabs located near the southern extents of Inlet Point, 17 m (56 ft) north of cobble beach, 11 m (35 ft) south of bench mark 1287 A 2003, and 3.44 m (11.3 ft) west of a 10 inch "x" chiseled into black granite boulder at grass line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 7 Station ID: 9451287 PUBLICATION DATE: 11/13/2003 Name: BEECHER PASS, WRANGELL NARROWS AK NOAA Chart: 17375 Latitude: 56° 35.7' N ( 56.59500) USGS Quad: PETERSBURG (C-3) Longitude: 132° 59.2' W (-132.98700) T I D A L B E N C H M A R K S BENCH MARK STAMPING: USE 54-89 1989 DESIGNATION: 945 1287 USE 54-89 MONUMENTATION: Tidal Station disk VM#: 17245 AGENCY: US Army Corps of Engineers (USCOE) IDB PID#: SETTING CLASSIFICATION: Bedrock OPUS PID: LATITUDE: 56° 35.7' N ( 56.59500) LONGITUDE: 132° 59.3' W (-132.98800) The bench mark is a disk set in bedrock, 22 m (73 ft) NW of bench mark 945 1287 TIDAL 3, 13.84 m (45.4 ft) NNW of bench mark NO 4 1929, 11 m (36 ft) west of bench mark 945 1287 TIDAL 1, and 7.50 m (24.6 ft) NE of bench mark NO 5 1929.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 7 Station ID: 9451287 PUBLICATION DATE: 11/13/2003 Name: BEECHER PASS, WRANGELL NARROWS AK NOAA Chart: 17375 Latitude: 56° 35.7' N ( 56.59500) USGS Quad: PETERSBURG (C-3) Longitude: 132° 59.2' W (-132.98700) T I D A L D A T U M S Tidal datums at BEECHER PASS, WRANGELL NARROWS based on: LENGTH OF SERIES: 2 MONTHS TIME PERIOD: August 2003 - September 2003 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9450460 KETCHIKAN, TONGASS NARROWS Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 4.716 MEAN HIGH WATER MHW = 4.445 MEAN TIDE LEVEL MTL = 2.457 MEAN SEA LEVEL MSL = 2.409 MEAN LOW WATER MLW = 0.468 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW NO 4 1929 6.340 1.895 945 1287 TIDAL 1 3.750 -0.695 945 1287 TIDAL 3 6.139 1.693 NO 5 1929 5.519 1.074 1287 A 2003 5.027 0.582 1287 B 2003 4.666 0.221 USE 54-89 1989 4.929 0.484
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 7 of 7 Station ID: 9451287 PUBLICATION DATE: 11/13/2003 Name: BEECHER PASS, WRANGELL NARROWS AK NOAA Chart: 17375 Latitude: 56° 35.7' N ( 56.59500) USGS Quad: PETERSBURG (C-3) Longitude: 132° 59.2' W (-132.98700) 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.