U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9415415 PUBLICATION DATE: 03/09/2004
Name: EDGERLEY ISLAND, NAPA RIVER
CA
NOAA Chart: 18654 Latitude: 38° 11.5' N ( 38.19170)
USGS Quad: NAPA Longitude: 122° 18.7' W (-122.31200)
To reach the tidal bench marksfrom Sear Point at Vallejo Heights on Mare Island,
proceed by boat north on Napa River, passing Knight, Russ, and Coons Islands on
the west bank of the river before reaching the southern tip of Edgerley Island
Marina. The bench marks are in the vicinity of the marina. The tide gage and
staff were located on piling at Napa River Light No. 13 (LL810).
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 5415 A 1979
DESIGNATION: 941 5415 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 8668
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 38° 11.6' N ( 38.19330) LONGITUDE: 122° 18.8' W (-122.31300)
The primary bench mark is a disk located in the bank on the north side of the
marina, east of the boat ramp, north of the main pier and west of Nelsons
Landing Coffee Shop. The bench mark is crimped to the top of a galvanized steel
rod driven 17.1 m (56 ft), and encased in a PVC pipe extending 0.24 m (0.8 ft)
above grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9415415 PUBLICATION DATE: 03/09/2004
Name: EDGERLEY ISLAND, NAPA RIVER
CA
NOAA Chart: 18654 Latitude: 38° 11.5' N ( 38.19170)
USGS Quad: NAPA Longitude: 122° 18.7' W (-122.31200)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5415 B 1979
DESIGNATION: 941 5415 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 8669
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 38° 11.6' N ( 38.19330) LONGITUDE: 122° 18.8' W (-122.31300)
The bench mark is a disk located at intersection of marsh and levee road (at a
curve around the marina), west of the marina dock, south of Nelsons Landing
Coffee Shop, and 4 m (14 ft) SW of centerline of dirt road, at a curve west of
the marina dock. The bench mark is crimped to the top of a galvanized steel rod
driven 19.5 m (64 ft), and encased in a PVC pipe extending 0.30 m (1.0 ft) above
grade.
BENCH MARK STAMPING: 5415 C 1979
DESIGNATION: 941 5415 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 8670
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 38° 11.6' N ( 38.19330) LONGITUDE: 122° 18.8' W (-122.31300)
The bench mark is a disk located SSW of the southern piling of channel marker
No. 13, at the southernmost point of the Island, 9.14 m (30.0 ft) SW of a
solitary piling in ground, and 1.28 m (4.2 ft) south of California Fish and Game
hunting sign. The bench mark is crimped to the top of a galvanized steel rod
driven 17.1 m (56 ft), and encased in a PVC pipe extending 15 cm (0.5 ft) above
grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9415415 PUBLICATION DATE: 03/09/2004
Name: EDGERLEY ISLAND, NAPA RIVER
CA
NOAA Chart: 18654 Latitude: 38° 11.5' N ( 38.19170)
USGS Quad: NAPA Longitude: 122° 18.7' W (-122.31200)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5415 D 1979
DESIGNATION: 941 5415 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 8671
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 38° 11.6' N ( 38.19330) LONGITUDE: 122° 18.8' W (-122.31300)
The bench mark is a disk located at wooden gate entrance to Nelsons Landing
Marina, 6.25 m (20.5 ft) SW of centerline of dirt/gravel road, 2.59 m (8.5 ft)
west of northern end of wooden gate with an END sign on it, and 0.91 m (3.0 ft)
NE of witness post. The bench mark is crimped to the top of a galvanized steel
rod driven 19.5 m (64 ft), and encased in a PVC pipe extending 0.24 m (0.8 ft)
above grade.
BENCH MARK STAMPING: 5415 E 1979
DESIGNATION: 941 5415 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 8672
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 38° 11.6' N ( 38.19330) LONGITUDE: 122° 18.8' W (-122.31300)
The bench mark is a disk located 25.91 m (85.0 ft) south of the SW corner of
1928 Milton Road, 4.63 m (15.2 ft) SW of centerline of Milton Road, and 0.46 m
(1.5 ft) SE of last telephone pole on west side of Milton Road. The bench mark
is crimped to the top of a galvanized steel rod driven 19.5 m (64 ft), and
encased in PVC pipe extending 0.24 m (0.8 ft) foot above grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9415415 PUBLICATION DATE: 03/09/2004
Name: EDGERLEY ISLAND, NAPA RIVER
CA
NOAA Chart: 18654 Latitude: 38° 11.5' N ( 38.19170)
USGS Quad: NAPA Longitude: 122° 18.7' W (-122.31200)
T I D A L D A T U M S
Tidal datums at EDGERLEY ISLAND, NAPA RIVER based on:
LENGTH OF SERIES: 5 MONTHS
TIME PERIOD: July 1979 - November 1979
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9414290 SAN FRANCISCO, SAN FRANCISCO BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.867
MEAN HIGH WATER MHW = 1.688
MEAN SEA LEVEL MSL = 0.984
MEAN TIDE LEVEL MTL = 0.976
MEAN LOW WATER MLW = 0.263
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
5415 A 1979 2.518 0.830
5415 B 1979 1.815 0.127
5415 C 1979 1.817 0.129
5415 D 1979 0.493 -1.195
5415 E 1979 0.539 -1.149
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9415415 PUBLICATION DATE: 03/09/2004
Name: EDGERLEY ISLAND, NAPA RIVER
CA
NOAA Chart: 18654 Latitude: 38° 11.5' N ( 38.19170)
USGS Quad: NAPA Longitude: 122° 18.7' W (-122.31200)
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.