U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 9451497 PUBLICATION DATE: 03/04/2009 Name: SAGINAW BAY, KUIU ISLAND AK NOAA Chart: 17368 Latitude: 56° 54.2' N ( 56.90333) USGS Quad: PORT ALEXANDER (D-1) Longitude: 134° 18.2' W (-134.30306) To reach the tidal bench marks from Cornwallis Point Light on Kuiu Island, proceed 3.7 km (2.0 nm) SW across Saginaw Bay to the small peninsula which points NE and is distinguished from the surrounding terrain by its light colored brush, and marks the western entrance of a small bay at the SW shore of the entrance to the Saginaw Bay. The bench marks are along the SE shore of the peninsula. The tide gage was also located on the SE shore of the peninsula. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: NO 1 1967 DESIGNATION: 945 1497 TIDAL 1 MONUMENTATION: Tidal Station disk VM#: 13099 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 56° 54.2' N ( 56.90330) LONGITUDE: 134° 18.2' W (-134.30300) The primary bench mark is a disk set on a high rock along the SE shore of the small peninsula, 100 m (328 ft) NNE of bench mark NO 3 1967, 20 m (66 ft) NNE of bench mark NO 2 1967, 5 m (16 ft) SE of the brush line, and 3 m (10 ft) NW of the apparent high water line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 9451497 PUBLICATION DATE: 03/04/2009 Name: SAGINAW BAY, KUIU ISLAND AK NOAA Chart: 17368 Latitude: 56° 54.2' N ( 56.90333) USGS Quad: PORT ALEXANDER (D-1) Longitude: 134° 18.2' W (-134.30306) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 2 1967 DESIGNATION: 945 1497 TIDAL 2 MONUMENTATION: Tidal Station disk VM#: 13100 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 56° 54.2' N ( 56.90330) LONGITUDE: 134° 18.2' W (-134.30300) The bench mark is a disk set along the SE shore of the small peninsula, 80 m (262 ft) NNE of bench mark NO 3 1967, 20 m (66 ft) SSW of bench mark NO 1 1967, 10 m (33 ft) NW of the apparent high water line, and 5 m (16 ft) SE of the brush line. BENCH MARK STAMPING: NO 3 1967 DESIGNATION: 945 1497 TIDAL 3 MONUMENTATION: Tidal Station disk VM#: 13101 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 56° 54.2' N ( 56.90330) LONGITUDE: 134° 18.2' W (-134.30300) The bench mark is a disk set on a high rock located along the SE shore of a small peninsula, 100 m (328 ft) SSW of bench mark NO 1 1967, 80 m (262 ft) SSW of bench mark NO 2 1967, 25 m (82 ft) east of the tree line, and 8 m (26 ft) NW of the apparent high water line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 9451497 PUBLICATION DATE: 03/04/2009 Name: SAGINAW BAY, KUIU ISLAND AK NOAA Chart: 17368 Latitude: 56° 54.2' N ( 56.90333) USGS Quad: PORT ALEXANDER (D-1) Longitude: 134° 18.2' W (-134.30306) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1497 D 1989 DESIGNATION: 945 1497 D MONUMENTATION: Tidal Station disk VM#: 13102 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 56° 54.2' N ( 56.90330) LONGITUDE: 134° 18.2' W (-134.30300) The bench mark is a disk set in bedrock on a small ledge that extends 2 m (6 ft) out from a cliff face, 45 m (147 ft) SW of bench mark NO 2 1967, 30 m (98 ft) WNW of bench mark NO 3 1967, and 2 m (7 ft) above the apparent high water line. BENCH MARK STAMPING: 1497 E 1989 DESIGNATION: 945 1497 E MONUMENTATION: Tidal Station disk VM#: 13103 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 56° 54.2' N ( 56.90330) LONGITUDE: 134° 18.2' W (-134.30300) The bench mark is a disk set in bedrock 94.34 m (309.5 ft) south of bench mark NO 2 1967, 19.05 m (62.5 ft) SSE of bench mark NO 3 1967, 10 m (33 ft) ENE of the treeline on a small east-west running outcrop, and 5 m (16 ft) above the apparent high water line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 9451497 PUBLICATION DATE: 03/04/2009 Name: SAGINAW BAY, KUIU ISLAND AK NOAA Chart: 17368 Latitude: 56° 54.2' N ( 56.90333) USGS Quad: PORT ALEXANDER (D-1) Longitude: 134° 18.2' W (-134.30306) T I D A L D A T U M S Tidal datums at SAGINAW BAY, KUIU ISLAND based on: LENGTH OF SERIES: 1 MONTH TIME PERIOD: March 1989 - April 1989 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 = 4.185 MEAN HIGH WATER MHW = 3.928 MEAN SEA LEVEL MSL = 2.215 MEAN TIDE LEVEL MTL = 2.197 MEAN LOW WATER MLW = 0.465 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 1 1967 6.382 2.454 NO 2 1967 5.205 1.277 NO 3 1967 6.151 2.223 1497 D 1989 5.050 1.122 1497 E 1989 5.380 1.453
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 9451497 PUBLICATION DATE: 03/04/2009 Name: SAGINAW BAY, KUIU ISLAND AK NOAA Chart: 17368 Latitude: 56° 54.2' N ( 56.90333) USGS Quad: PORT ALEXANDER (D-1) Longitude: 134° 18.2' W (-134.30306) 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.