U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 09/16/1988
Station ID: 8638916 SUPERCEDED DATE: 04/21/2003
Name: LYNNHAVEN, LONG CREEK
VIRGINIA
NOAA Chart: 12254 Latitude: 36° 54.2' N
USGS Quad: CAPE HENRY Longitude: 76° 4.2' W
To reach the tidal bench marks from the intersection of Adam Keeling Road and
Great Neck Road (State Highway 615) in Virginia Beach, proceed north over Broad
Bay Canal bridge and then over Long Creek bridge. The bench marks are located
on the bridge over Long Creek and on the west side of the bridge in the vicinity
of Dockside Restaurant and Lynnhaven Propeller Service. The tide gage and staff
were located on the west side of Lynnhaven Propeller Service.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 2 1963
MONUMENTATION: Survey Disk VM#: 3474
AGENCY: PID:
SETTING CLASSIFICATION: Bridge Support
The bench mark is set vertically in the NW side of the State Highway 615 bridge
over Long Creek, directly west of Dockside Restaurant.
BENCH MARK STAMPING: NO 3 1963
MONUMENTATION: Survey Disk VM#: 3475
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Flag Pole Base
The bench mark is set in the concrete base of a flag pole about 1 foot (0.3 m)
east of the flag pole, 142 feet (43 m) west of Bench Mark NO 2 1963, and 1 foot
(0.3 m) NE of a pumphouse.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 09/16/1988
Station ID: 8638916 SUPERCEDED DATE: 04/21/2003
Name: LYNNHAVEN, LONG CREEK
VIRGINIA
NOAA Chart: 12254 Latitude: 36° 54.2' N
USGS Quad: CAPE HENRY Longitude: 76° 4.2' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 4 1969
MONUMENTATION: Survey Disk VM#: 3476
AGENCY: PID:
SETTING CLASSIFICATION: Bridge Abutment
The bench mark is set flush in the top of the SE wing abutment of the State
Highway 615 bridge over Long Creek.
BENCH MARK STAMPING: NO STAMPING 1
MONUMENTATION: Lag Bolt VM#: 3477
AGENCY: PID:
SETTING CLASSIFICATION: Telephone Pole
The bench mark is a lag bolt screwed into VEPCO telephone pole #E+R N-71
SP537440 located NW of the gas station, directly north of Lynnhaven Propeller
Service, and 1 foot (0.3 m) above the ground.
BENCH MARK STAMPING: NO STAMPING 2
MONUMENTATION: Lag Bolt VM#: 3478
AGENCY: PID:
SETTING CLASSIFICATION: Telephone Pole
The bench mark is a lag bolt screwed into VEPCO telephone pole #E+R N-68 SPSC
506440 (with a plate stamped F671) NE of Lynnhaven Propeller Service.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 09/16/1988
Station ID: 8638916 SUPERCEDED DATE: 04/21/2003
Name: LYNNHAVEN, LONG CREEK
VIRGINIA
NOAA Chart: 12254 Latitude: 36° 54.2' N
USGS Quad: CAPE HENRY Longitude: 76° 4.2' W
T I D A L D A T U M S
Tidal datums at LYNNHAVEN, LONG CREEK based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: DECEMBER 1977
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8638610 HAMPTON ROADS
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (12/19/1977) = 4.18
MEAN HIGHER HIGH WATER MHHW = 2.02
MEAN HIGH WATER MHW = 1.81
MEAN TIDE LEVEL MTL = 0.97
MEAN LOW WATER MLW = 0.13
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (01/11/1978) = -1.87
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
NO 2 1963 9.56 7.75
NO 3 1963 4.91 3.10
NO 4 1969 27.04 25.23
NO STAMPING 1 7.09 5.28
NO STAMPING 2 7.18 5.37
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 09/16/1988
Station ID: 8638916 SUPERCEDED DATE: 04/21/2003
Name: LYNNHAVEN, LONG CREEK
VIRGINIA
NOAA Chart: 12254 Latitude: 36° 54.2' N
USGS Quad: CAPE HENRY Longitude: 76° 4.2' W
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 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.