U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 9414688 PUBLICATION DATE: 08/03/2004 Name: SAN LEANDRO MARINA, SAN FRANCISCO BAY CA NOAA Chart: 18651 Latitude: 37° 41.7' N ( 37.69500) USGS Quad: SAN LEANDRO Longitude: 122° 11.5' W (-122.19200) To reach the tidal bench marks from San Leandro, proceed SW on Marina Boulevard or Fairway Drive to Neptune Drive in San Leandro, then turn on Neptune Drive towards North Dike Road (between Marina Boulevard and Fairway Drive), then turn and proceed west on North Dike Road to the Blue Dolphin Restaurant, then south to Mulford Point on the north side of the entrance to the San Leandro Channel Harbor. The bench marks are located around the boat docking facilities. The tide gage and staff were located on channel marker piling 23. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: TIDAL BM 4 1974 DESIGNATION: 941 4688 TIDAL 4 MONUMENTATION: Tidal Station disk VM#: 8382 AGENCY: National Ocean Survey (NOS) IDB PID#: HT2331 SETTING CLASSIFICATION: Concrete curved wall OPUS PID: LATITUDE: 37° 41.7' N ( 37.69500) LONGITUDE: 122° 11.6' W (-122.19300) The primary bench mark is a disk set vertically in the south face of a curved concrete wall that bears a mosaic tile mural on its north face located at the south end of the westernmost parking lot of San Leandro Marina, 6 m (19 ft) south of the south end of the parking lot, 0.37 m (1.2 ft) east of the west end of the wall, and 1.10 m (3.6 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 9414688 PUBLICATION DATE: 08/03/2004 Name: SAN LEANDRO MARINA, SAN FRANCISCO BAY CA NOAA Chart: 18651 Latitude: 37° 41.7' N ( 37.69500) USGS Quad: SAN LEANDRO Longitude: 122° 11.5' W (-122.19200) T I D A L B E N C H M A R K S BENCH MARK STAMPING: TIDAL BM 6 1974 DESIGNATION: 941 4688 TIDAL 6 MONUMENTATION: Tidal Station disk VM#: 8384 AGENCY: National Ocean Survey (NOS) IDB PID#: HT2329 SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 37° 41.9' N ( 37.69830) LONGITUDE: 122° 11.6' W (-122.19300) The bench mark is a disk set flush in the top of the concrete foundation that supports the inshore end of the northernmost pier leading to Float A, 18 m (60 ft) south of the SW post supporting the roof over the main (west) entrance to the Blue Dolphin Restaurant, 7.10 m (23.3 ft) east of the east curb of the parking lot, 0.12 m (0.4 ft) south of the north edge of the foundation, and 0.43 m (1.4 ft) below the top of the pier. BENCH MARK STAMPING: 4688 B 1976 DESIGNATION: 941 4688 B TIDAL MONUMENTATION: Tidal Station disk VM#: 8386 AGENCY: National Ocean Survey (NOS) IDB PID#: HT2327 SETTING CLASSIFICATION: Copper clad steel rod OPUS PID#: HT2327 LATITUDE: 37° 42.1' N ( 37.70170) LONGITUDE: 122° 11.4' W (-122.19000) The bench mark is a disk located at the entrance to the San Leandro Marina on Marina Boulevard, 43 m (142 ft) SW of the centerline of the intersection of Marina Boulevard and the west shoreline road, 16 m (51 ft) NW of the centerline of Marina Boulevard, 15 m (50 ft) NNE of a pumping station building, 6.86 m (22.5 ft) SE of the west shoreline within the marine grounds, and 0.91 m (3.0 ft) NNW from the NNW vertical pipe making up a metal sculpture (shape of a sailboat). The mark is crimped to the top of a copper-clad steel rod driven 21.5 m (70.5 ft) to substantial refusal.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 9414688 PUBLICATION DATE: 08/03/2004 Name: SAN LEANDRO MARINA, SAN FRANCISCO BAY CA NOAA Chart: 18651 Latitude: 37° 41.7' N ( 37.69500) USGS Quad: SAN LEANDRO Longitude: 122° 11.5' W (-122.19200) T I D A L B E N C H M A R K S BENCH MARK STAMPING: PARCOURSE NW 1982 DESIGNATION: PARCOURSE NW MONUMENTATION: Survey disk VM#: 8387 AGENCY: National Ocean Survey (NOS) IDB PID#: HT3757 SETTING CLASSIFICATION: Irregular mass of concrete OPUS PID: LATITUDE: 37° 41.6' N ( 37.69330) LONGITUDE: 122° 11.5' W (-122.19200) The bench mark is a disk set in a 15-inch diameter concrete monument, 36 m (118 ft) west of a metal framed wooden bench, 34 m (110 ft) from the nearest edge of the Par Course Vault Bar No. 10 sign, 33 m (108 ft) west of the west compass range marker, and 0.15 m (0.5 ft) below the monument surface.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 9414688 PUBLICATION DATE: 08/03/2004 Name: SAN LEANDRO MARINA, SAN FRANCISCO BAY CA NOAA Chart: 18651 Latitude: 37° 41.7' N ( 37.69500) USGS Quad: SAN LEANDRO Longitude: 122° 11.5' W (-122.19200) T I D A L D A T U M S Tidal datums at SAN LEANDRO MARINA, SAN FRANCISCO BAY based on: LENGTH OF SERIES: 8 MONTHS TIME PERIOD: May 1975 - December 1975 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9414750 ALAMEDA, SAN FRANCISCO BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 2.264 MEAN HIGH WATER MHW = 2.069 MEAN TIDE LEVEL MTL = 1.212 MEAN SEA LEVEL MSL = 1.194 MEAN LOW WATER MLW = 0.355 North American Vertical Datum NAVD88 = 0.187 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW TIDAL BM 4 1974 5.345 3.276 TIDAL BM 6 1974 2.549 0.480 4688 B 1976 2.809 0.740 PARCOURSE NW 1982 4.970 2.901
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 9414688 PUBLICATION DATE: 08/03/2004 Name: SAN LEANDRO MARINA, SAN FRANCISCO BAY CA NOAA Chart: 18651 Latitude: 37° 41.7' N ( 37.69500) USGS Quad: SAN LEANDRO Longitude: 122° 11.5' W (-122.19200) 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.