U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 06/30/2000
Station ID: 8447435 SUPERCEDED DATE: 04/21/2003
Name: CHATHAM, LYDIA COVE
MASSACHUSETTS
NOAA Chart: 13248 Latitude: 41° 41.6' N
USGS Quad: CHATHAM Longitude: 69° 57.0' W
From the intersection of State Highway 28 and Main Street in the village of
Chatham, proceed one block east on Main Street, turn left on Seaview Street and
continue to Shore Road, then left and north on Shore Road to the Chatham
Municipal Fish Pier on the right. The bench marks are located in the vicinity of
the fish pier and in town. The tide gage was located in the SE corner of the
boat basin on the south side of the fish packing house.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7435 A 1994
DESIGNATION: 844 7435 A
MONUMENTATION: Tidal Station disk VM#: 13533
AGENCY: National Ocean Service (NOS) PID:
SETTING CLASSIFICATION: Concrete apron
The primary bench mark is a disk set flush in the SW corner of a 2.44 m (8.0 ft)
wide concrete apron located at the SE corner of the Chatham Municipal Fish Pier,
31.70 m (104.0 ft) SE of the SE side of the fish packing house on the wharf,
22.07 m (72.4 ft) NE of the SW edge of the parking lot, 2.90 m (9.51 ft) SW of
the NE face of the pier, set flush with ground.
BENCH MARK STAMPING: 7435 B 1985
DESIGNATION: 844 7435 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 13534
AGENCY: National Ocean Service (NOS) PID#: AA7166
SETTING CLASSIFICATION: Concrete pedistal
The bench mark is a disk set in the north corner of the 2 m x 2 m (6 ft x 6 ft)
concrete pedistal for electrical transformer No. 60/010 located at the Chatham
Municipal Fish Pier, 31.55 m (103.5 ft) south of the south corner of the
Nickerson Fish Market, 11.95 m (39.2 ft) east of the SE corner of the
Dockmasters Building, 4.91 m (16.1 ft) NW of a red and white fire hydrant, and
0.20 m (0.67 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 06/30/2000
Station ID: 8447435 SUPERCEDED DATE: 04/21/2003
Name: CHATHAM, LYDIA COVE
MASSACHUSETTS
NOAA Chart: 13248 Latitude: 41° 41.6' N
USGS Quad: CHATHAM Longitude: 69° 57.0' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7435 D 1985
DESIGNATION: 844 7435 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 13536
AGENCY: National Ocean Service (NOS) PID#: AB7970
SETTING CLASSIFICATION: Boulder
The bench mark is a disk set flush in a granite boulder on a rock sea-wall north
of Chatham Municipal Fish Pier, 36.33 m (119.2 ft) north of the south face of
Nickerson Fish Market, 11.28 m (37.0 ft) north of the south end of the sea wall,
3.60 m (11.8 ft) east of the west edge of a bushy hill.
BENCH MARK STAMPING: 7435 E 1985
DESIGNATION: 844 7435 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 13537
AGENCY: National Ocean Service (NOS) PID#: AB7971
SETTING CLASSIFICATION: Boulder
The bench mark is a disk set flush in a granite boulder on a rock sea-wall north
of the Chatham Municipal Fish Pier, 84 m (274 ft) north of bench mark 7435 D
1985, and 1.83 m (6.0 ft) east of the east face of the rock sea-wall.
BENCH MARK STAMPING:
DESIGNATION: 844 7435 NO 1
ALIAS: NO STAMPING 1
MONUMENTATION: Bolt VM#: 13633
AGENCY: Massachusetts Geodetic Survey PID:
SETTING CLASSIFICATION: Mat foundation
The bench mark is a copper plug set in the NE corner of the third step from the
bottom at the "Pioneers of Chatham" memorial in front of the Eldridge Public
Library on Main Street in the village of Chatham.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 06/30/2000
Station ID: 8447435 SUPERCEDED DATE: 04/21/2003
Name: CHATHAM, LYDIA COVE
MASSACHUSETTS
NOAA Chart: 13248 Latitude: 41° 41.6' N
USGS Quad: CHATHAM Longitude: 69° 57.0' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 844 7435 111M
ALIAS: NO STAMPING 2
MONUMENTATION: Traverse Station disk VM#: 13634
AGENCY: Massachusetts Geodetic Survey PID:
SETTING CLASSIFICATION: Concrete monument
The bench mark is a disk set in a concrete monument on a wooded knoll behind the
Chatham Bank near the intersection of Main Street and Queen Anne's Road at the
rotary in Chatham, 76 m (249 ft) west of State Highway 28, 43 m (141 ft) NW of
power pole No. 14, 22 m (73 ft) north of the centerline of Queen Anne's Road, 16
m (52 ft) east of the NE corner of a house, 2 m (7 ft) above the road, and at
ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 06/30/2000
Station ID: 8447435 SUPERCEDED DATE: 04/21/2003
Name: CHATHAM, LYDIA COVE
MASSACHUSETTS
NOAA Chart: 13248 Latitude: 41° 41.6' N
USGS Quad: CHATHAM Longitude: 69° 57.0' W
T I D A L D A T U M S
Tidal datums at CHATHAM, LYDIA COVE based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: August 1994 - October 1994
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8449130 NANTUCKET ISLAND, NANTUCKET SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.585
MEAN HIGH WATER MHW = 1.462
North American Vertical Datum NAVD88 = 0.816
MEAN SEA LEVEL MSL = 0.771
MEAN TIDE LEVEL MTL = 0.758
MEAN LOW WATER MLW = 0.054
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7435 A 1994 2.587 1.125
7435 B 1985 4.648 3.187
7435 D 1985 2.719 1.257
7435 E 1985 2.794 1.333
844 7435 NO 1 7.738 6.276
844 7435 111M 14.625 13.164
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 06/30/2000
Station ID: 8447435 SUPERCEDED DATE: 04/21/2003
Name: CHATHAM, LYDIA COVE
MASSACHUSETTS
NOAA Chart: 13248 Latitude: 41° 41.6' N
USGS Quad: CHATHAM Longitude: 69° 57.0' 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.