U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 9410971 PUBLICATION DATE: 12/08/2011 Name: PRISONERS HARBOR, SANTA CRUZ IS. CA NOAA Chart: 18727 Latitude: 34° 1.2' N ( 34.02000) USGS Quad: SANTA CRUZ ISLAND Longitude: 119° 41.0' W (-119.68300) To reach the tidal bench marks proceed 32.2 km (20.0 mi) due south of Santa Barbara by boat across Santa Barbara Channel to Prisoners Harbor located on north central coast of the Island in the Pacific Ocean. Then proceed along dirt road (running east-west from dry canyon wash to boat ramp just past wooden pier), parallel to sand and gravel beach along harbor shoreline. The bench marks are located in the vicinity. The tide gauge and staff were located on the NE end of the Prisoners Harbor Pier. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 1 1934 MONUMENTATION: Tidal Station disk VM#: 8016 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: EW5798 SETTING CLASSIFICATION: Concrete post OPUS PID: LATITUDE: 34° 1.2' N ( 34.02000) LONGITUDE: 119° 41.0' W (-119.68300) The primary bench mark is a disk set in a concrete post 10.76 m (35.3 ft) SW of SE corner of wooden pier, 62.64 m (205.5 ft) west of the west corner of a fence around an abandoned 2-story concrete ranch house, 5.18 m (17.0 ft) west of the centerline of a dirt road (from wharf passed warehouse to farm houses), 1.68 m (5.5 ft) SE of north corner of warehouse, and 0.30 m (1.0 ft) east of the east wall of a double gabled red brick warehouse. BENCH MARK STAMPING: 4 1946 MONUMENTATION: Tidal Station disk VM#: 8017 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: EW5800 SETTING CLASSIFICATION: Cemented in Drill Hole OPUS PID: LATITUDE: 34° 1.2' N ( 34.02000) LONGITUDE: 119° 41.0' W (-119.68300) The bench mark is a disk set in top of a long sloping sandstrone outcrop, 224.03 m (735.0 ft) west of the SW corner of wooden pier, 160 m (525 ft) west of SW corner of US Navy Steel floating pier, 10.36 m (34.0 ft) NW of the NW corner of long graveled beach, and 2.44 m (8.0 ft) east of the east face of a steep bluff.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 9410971 PUBLICATION DATE: 12/08/2011 Name: PRISONERS HARBOR, SANTA CRUZ IS. CA NOAA Chart: 18727 Latitude: 34° 1.2' N ( 34.02000) USGS Quad: SANTA CRUZ ISLAND Longitude: 119° 41.0' W (-119.68300) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 0971 A 1977 MONUMENTATION: Tidal Station disk VM#: 8018 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 34° 1.2' N ( 34.02000) LONGITUDE: 119° 41.0' W (-119.68300) The bench mark is a disk located in line of four pine trees, 31.00 m (101.7 ft) SW of the SW corner of wooden pier, 29.99 m (98.4 ft) SE of an excavated boat ramp centerline, 14.33 m (47.0 ft) north of steep bluff, 3 m (10 ft) SW and 2.90 m (9.5 ft) NW of middle two of four pine trees. The site is marked by rock cairn. The bench mark is set 0.09 m (0.3 ft) below ground level, fastened to a galvanized steel rod driven 3 m (10 ft) to bedrock refusal. BENCH MARK STAMPING: 0971 B 1977 MONUMENTATION: Tidal Station disk VM#: 8019 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 34° 1.2' N ( 34.02000) LONGITUDE: 119° 41.0' W (-119.68300) The bench mark is a disk located 91.99 m (301.8 ft) west of south end of wooden pier, 44.99 m (147.6 ft) west of centerline of excavated boat ramp, 9.75 m (32.0 ft) north of steep bluff, 8 m (26.0 ft) south of ground and rocky beach coastline, and 1.22 m (4.0 ft) south of a large pine tree. The bench mark is set 0.09 m (0.3 ft) below ground level, fastened to a galvanized steel rod driven 7 m (23 ft) to bedrock refusal.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 9410971 PUBLICATION DATE: 12/08/2011 Name: PRISONERS HARBOR, SANTA CRUZ IS. CA NOAA Chart: 18727 Latitude: 34° 1.2' N ( 34.02000) USGS Quad: SANTA CRUZ ISLAND Longitude: 119° 41.0' W (-119.68300) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 0971 C 1977 MONUMENTATION: Tidal Station disk VM#: 8020 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 34° 1.2' N ( 34.02000) LONGITUDE: 119° 41.0' W (-119.68300) The bench mark is a disk located 22 m (72 ft) ESE of SE corner of wooden pier, 58.00 m (190.3 ft) ESE of main gate across road leading from pier area, 11 m (36 ft) south of intersection of road to Navy facility and road to ranch, and 3.66 m (12.0 ft) NW of west end of gate across road to ranch house and entrance to canyon. The bench mark is set 0.09 m (0.3 ft) below ground level, fastened to a galvanized steel rod driven 10 m (33 ft) to bedrock refusal.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 9410971 PUBLICATION DATE: 12/08/2011 Name: PRISONERS HARBOR, SANTA CRUZ IS. CA NOAA Chart: 18727 Latitude: 34° 1.2' N ( 34.02000) USGS Quad: SANTA CRUZ ISLAND Longitude: 119° 41.0' W (-119.68300) T I D A L D A T U M S Tidal datums at PRISONERS HARBOR, SANTA CRUZ IS. based on: LENGTH OF SERIES: 4 MONTHS TIME PERIOD: April 1978 - July 1978 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9411340 SANTA BARBARA, PACIFIC OCEAN Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 1.600 MEAN HIGH WATER MHW = 1.368 MEAN TIDE LEVEL MTL = 0.829 MEAN SEA LEVEL MSL = 0.822 MEAN LOW WATER MLW = 0.290 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 1 1934 3.521 2.153 4 1946 2.586 1.218 0971 A 1977 3.759 2.391 0971 B 1977 3.614 2.246 0971 C 1977 4.801 3.433
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 9410971 PUBLICATION DATE: 12/08/2011 Name: PRISONERS HARBOR, SANTA CRUZ IS. CA NOAA Chart: 18727 Latitude: 34° 1.2' N ( 34.02000) USGS Quad: SANTA CRUZ ISLAND Longitude: 119° 41.0' W (-119.68300) 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.