U.S. DEPARTMENT OF COMMERCE
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National Ocean Service
Datums Page Page 1 of 7
Station ID: 8447505 PUBLICATION DATE: 02/05/2004
Name: CHATHAM, STAGE HARBOR
MA
NOAA Chart: 13248 Latitude: 41° 40.0' N ( 41.66670)
USGS Quad: CHATHAM Longitude: 69° 58.0' W ( -69.96670)
To reach the tidal bench marks from the intersection of State Routes 137 and 28
in Chatham, proceed west on State Route 28 for 5.3 km (3.3 mi) to a rotary, go
one-quater of the way around the rotary to Stage Harbor Road, then proceed south
on Stage Harbor Road for 1.9 km (1.2 mi) to Champlain Road, proceed west on
Champlain Road for 0.2 km (0.1 mi) to Port Fortune Lane, then make a left onto
Port Fortune Lane and proceed south for 0.2 km (0.1 mi) to Hoyts Pier. The
bench marks are near the pier, near the fishing pier east of Hoyts Pier, and on
the drawbridge on Bridge Street. The tide guage and staff were located on the
SW corner of Hoyts Pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: BM NO 4 1952
DESIGNATION: 844 7505 TIDAL 4
MONUMENTATION: Bench Mark disk VM#: 12050
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AB7967
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 41° 40.0' N ( 41.66670) LONGITUDE: 69° 58.1' W ( -69.96830)
The primary bench mark is a disk set in the east end of the sea wall located at
the NW end of Hoyts Pier, 38.01 m (124.7 ft) east of the extended centerline of
Port Fortune Lane, 18.11 m (59.4 ft) SSW of the SW corner of the storage
building located north of the pier, 3.51 m (11.5 ft) SSW of the NW corner of the
Holt Trap Company dock, 0.30 m (1.0 ft) west of the east end of the sea wall,
and 0.49 m (1.6 ft) below the level of the dock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 8447505 PUBLICATION DATE: 02/05/2004
Name: CHATHAM, STAGE HARBOR
MA
NOAA Chart: 13248 Latitude: 41° 40.0' N ( 41.66670)
USGS Quad: CHATHAM Longitude: 69° 58.0' W ( -69.96670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7505 A 1992
DESIGNATION: 844 7505 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 12051
AGENCY: National Ocean Service (NOS) IDB PID#: AB7966
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 41° 40.0' N ( 41.66670) LONGITUDE: 69° 58.1' W ( -69.96830)
The bench mark is a disk set in the top of a north-south oriented concrete sea
wall located west of Hoyts Pier, 5.70 m (18.7 ft) west of the centerline of Port
Fortune Lane, 40 m (130 ft) west of the NW corner of the storage building
located north of the pier, 5.27 m (17.3 ft) north of the south end of the sea
wall, 4 m (13 ft) south of the southernmost concrete post along the sea wall.
BENCH MARK STAMPING: 7505 B 1992
DESIGNATION: 844 7505 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 12052
AGENCY: National Ocean Service (NOS) IDB PID#: AB7968
SETTING CLASSIFICATION: Concrete boat ramp OPUS PID:
LATITUDE: 41° 40.0' N ( 41.66670) LONGITUDE: 69° 58.1' W ( -69.96830)
The bench mark is a disk set in the NW corner of the concrete boat ramp located
SE of Hoyts Pier, 33.07 m (108.5 ft) SW of the SW corner of a steel sheet
bulkhead pile on the property east of 21 Port Fortune Road, 28.07 m (92.1 ft)
SSE of the SE corner of the storage building north of the pier, 23.35 m (76.6
ft) south of the SW corner of the deck on the south side of the house at 21 Port
Fortune Road, and 0.09 m (0.3 ft) east of the west edge of the ramp.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8447505 PUBLICATION DATE: 02/05/2004
Name: CHATHAM, STAGE HARBOR
MA
NOAA Chart: 13248 Latitude: 41° 40.0' N ( 41.66670)
USGS Quad: CHATHAM Longitude: 69° 58.0' W ( -69.96670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7505 C 1992
DESIGNATION: 844 7505 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 12053
AGENCY: National Ocean Service (NOS) IDB PID#: AB7965
SETTING CLASSIFICATION: Concrete loading dock OPUS PID:
LATITUDE: 41° 40.0' N ( 41.66670) LONGITUDE: 69° 58.0' W ( -69.96670)
The bench mark is a disk set in the NE corner of the concrete loading platform
for the Chatham Fisheries building located at 3 Champlain Road, 45.81 m (150.3
ft) south of the centerline of Champlain Road, 23.93 m (78.5 ft) SSW of utility
pole #409, 6.71 m (22.0 ft) SW of the SW corner of the Chatham Harbormaster
building at 613 Stage Harbor Road, 2.50 m (8.2 ft) north of the north face of
the Chatham Fisheries building, 0.30 m (1.0 ft) SSE of a horseshoe set in the NE
corner of the loading platform, and 0.64 m (2.1 ft) above the ground.
BENCH MARK STAMPING: 7505 D 1992
DESIGNATION: 844 7505 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 12054
AGENCY: National Ocean Service (NOS) IDB PID#: AB7964
SETTING CLASSIFICATION: Concrete bridge pier OPUS PID:
LATITUDE: 41° 40.2' N ( 41.67000) LONGITUDE: 69° 57.7' W ( -69.96170)
The bench mark is a disk set in the eastern end of the NW concrete bridge peir
of the Bridge Road bridge over Mill Pond, 37 m (122 ft) east of the NW traffic
light, 17.13 m (56.2 ft) NE of the NE corner of a small building at the SW
corner of the pier, 4.42 m (14.5 ft) north of the centerline of Bridge Road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8447505 PUBLICATION DATE: 02/05/2004
Name: CHATHAM, STAGE HARBOR
MA
NOAA Chart: 13248 Latitude: 41° 40.0' N ( 41.66670)
USGS Quad: CHATHAM Longitude: 69° 58.0' W ( -69.96670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 844 7505 TIDAL 1
ALIAS: G35, NO STAMPING 1
MONUMENTATION: Bolt VM#: 12055
AGENCY: Massachusettes Geodetic Survey (MGS) IDB PID#: AB7963
SETTING CLASSIFICATION: Granite step OPUS PID:
LATITUDE: 41° 40.8' N ( 41.68000) LONGITUDE: 69° 57.5' W ( -69.95830)
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 near the intersection of Main Street
and Library Lane, 24.29 m (79.7 ft) SW of the main entrance door if the Eldridge
Public Library, 18.29 m (60.0 ft) SE of the centerline of Library Lane, 8.11 m
(26.6 ft) NE of the centerline of Main Street, and 1.01 m (3.3 ft) above the
level of the street.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8447505 PUBLICATION DATE: 02/05/2004
Name: CHATHAM, STAGE HARBOR
MA
NOAA Chart: 13248 Latitude: 41° 40.0' N ( 41.66670)
USGS Quad: CHATHAM Longitude: 69° 58.0' W ( -69.96670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 111M
ALIAS: NO STAMPING 2
MONUMENTATION: Survey disk VM#: 12056
AGENCY: Massachusettes Department of Public
Works (MDPW) IDB PID#: AB7962
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 41° 40.9' N ( 41.68170) LONGITUDE: 69° 57.8' W ( -69.96330)
The bench mark is a disk set in the top of a concrete monument located near the
intersection of Main Street and Queen Annes Road in Chatham, 61.59 m (202.4 ft)
SW of the centerline of State Route 28, 33.31 m (109.3 ft) SW of the SW corner
of the cape cod bank, 22.19 m (72.8 ft) north of the centerline of Queen Ann
Road, 15.00 m (49.2 ft) east of the NE corner of a house, 0.30 m (1.0 ft) NE of
a witness post, and 2.99 m (9.8 ft) above the level of the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8447505 PUBLICATION DATE: 02/05/2004
Name: CHATHAM, STAGE HARBOR
MA
NOAA Chart: 13248 Latitude: 41° 40.0' N ( 41.66670)
USGS Quad: CHATHAM Longitude: 69° 58.0' W ( -69.96670)
T I D A L D A T U M S
Tidal datums at CHATHAM, STAGE HARBOR based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: August 1992 - September 1992
TIDAL EPOCH: 1983-2001
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 = 1.395
MEAN HIGH WATER MHW = 1.283
North American Vertical Datum NAVD88 = 0.818
MEAN SEA LEVEL MSL = 0.712
MEAN TIDE LEVEL MTL = 0.681
MEAN LOW WATER MLW = 0.079
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
BM NO 4 1952 2.291 1.008
7505 A 1992 3.156 1.873
7505 B 1992 2.281 0.998
7505 C 1992 2.713 1.430
7505 D 1992 3.268 1.985
844 7505 TIDAL 1 7.744 6.461
111M 14.632 13.349
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8447505 PUBLICATION DATE: 02/05/2004
Name: CHATHAM, STAGE HARBOR
MA
NOAA Chart: 13248 Latitude: 41° 40.0' N ( 41.66670)
USGS Quad: CHATHAM Longitude: 69° 58.0' W ( -69.96670)
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.