U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8444525 PUBLICATION DATE: 04/21/2003
Name: NUT ISLAND, QUINCY BAY
MASSACHUSETTS
NOAA Chart: 13270 Latitude: 42° 16.8' N
USGS Quad: HULL Longitude: 70° 57.2' W
To reach the tidal bench marks from I-93 South in Boston, take Exit 12 to Route
3A South and bear left to the Squantum/Wollaston Beach exit and Sea Street, then
go 5.0 km (3.1 mi) to the entrance of the Nut Island Headworks facility. The
bench marks are on the property of the headworks facility. The tide gage was
located on the inshore end of the concrete pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NI 8
DESIGNATION: 844 4525 NI 8
MONUMENTATION: Survey disk VM#: 16249
AGENCY: Massachusetts Geodetic Survey (MGS) PID:
SETTING CLASSIFICATION: Concrete pier
The primary bench mark is a disk set flush in the concrete cap on the east side
of the Nut Island headworks pier, 25.02 m (82.1 ft) south of the north end of
the pier, 6.49 m (21.3 ft) north of the center of a bollard, 3.41 m (11.2 ft)
east of the center of the pier, and 1.07 m (3.5 ft) west of the east edge.
BENCH MARK STAMPING: 4525 A 2000
DESIGNATION: 844 4525 A
MONUMENTATION: Tidal Station disk VM#: 16250
AGENCY: National Ocean Service (NOS) PID:
SETTING CLASSIFICATION: Concrete pier
The bench mark is a disk set flush in the concrete cap on the east side of the
Nut Island headworks pier, 24.81 m (81.4 ft) NW of the second light pole on the
east side of the pier, 9.63 m (31.6 ft) NE of the first light pole on the pier,
4.11 m (13.5 ft) south of the center of the pier, and 0.46 m (1.5 ft) west of
the east edge of the pier.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8444525 PUBLICATION DATE: 04/21/2003
Name: NUT ISLAND, QUINCY BAY
MASSACHUSETTS
NOAA Chart: 13270 Latitude: 42° 16.8' N
USGS Quad: HULL Longitude: 70° 57.2' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4525 B 2000
DESIGNATION: 844 4525 B
MONUMENTATION: Tidal Station disk VM#: 16251
AGENCY: National Ocean Service (NOS) PID:
SETTING CLASSIFICATION: Concrete well cap
The bench mark is a disk set in a concrete well cap with four goose necked vent
pipes on the NE side of the facility building, 25.79 m (84.6 ft) NNE of the SE
corner of a chainlink fence around a parking lot, 25.51 m (83.7 ft) SSE of the
centerline of the road leading to the pier, 11.80 m (38.7 ft) SE of the NE
corner of the fence, 8.41 m (27.6 ft) east of the side of the fence, and 0.40 m
(1.3 ft) above the ground.
BENCH MARK STAMPING: 4525 C 2000
DESIGNATION: 844 4525 C
MONUMENTATION: Tidal Station disk VM#: 16252
AGENCY: National Ocean Service (NOS) PID:
SETTING CLASSIFICATION: Concrete pad
The bench mark is a disk set in the NW corner of a 3.00 m (9.8 ft) x 4.30 m
(14.1 ft) concrete pad with steel doors and a 0.95 m (3.1 ft) x 0.95 m (3.1 ft)
stainless vent, on the NW side of the facility building and near the bike path,
44.50 m (146.0 ft) NE of a stainless vent, 20.20 m (66.3 ft) NNW of the westerly
of two flagpoles in front of the building, 3.60 m (11.8 ft) ESE of a asphalt
bike path, and at ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8444525 PUBLICATION DATE: 04/21/2003
Name: NUT ISLAND, QUINCY BAY
MASSACHUSETTS
NOAA Chart: 13270 Latitude: 42° 16.8' N
USGS Quad: HULL Longitude: 70° 57.2' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4525 D 2000
DESIGNATION: 844 4525 D
MONUMENTATION: Tidal Station disk VM#: 16253
AGENCY: National Ocean Service (NOS) PID:
SETTING CLASSIFICATION: Concrete pad
The bench mark is a disk set flush in a concrete pad for a 4 ft (1 m) square
stainless steel vent, on the north side of the property on a small hill, 137 m
(450 ft) NWof the facility building, 36.55 m (119.9 ft) NNW of an asphalt
jogging trail, 20.00 m (65.6 ft) east of a jogging trail, and 4.60 m (15.1 ft)
west of a concrete and steel vent.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8444525 PUBLICATION DATE: 04/21/2003
Name: NUT ISLAND, QUINCY BAY
MASSACHUSETTS
NOAA Chart: 13270 Latitude: 42° 16.8' N
USGS Quad: HULL Longitude: 70° 57.2' W
T I D A L D A T U M S
Tidal datums at NUT ISLAND, QUINCY BAY based on:
LENGTH OF SERIES: 14 Months
TIME PERIOD: September 2000 - October 2001
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8443970 BOSTON, BOSTON HARBOR
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (03/06/2001) = 3.973
MEAN HIGHER HIGH WATER (MHHW) = 3.113
MEAN HIGH WATER (MHW) = 2.976
MEAN SEA LEVEL (MSL) = 1.574
MEAN TIDE LEVEL (MTL) = 1.540
MEAN LOW WATER (MLW) = 0.104
MEAN LOWER LOW WATER (MLLW) = 0.000
LOWEST OBSERVED WATER LEVEL (02/11/2001) = -0.954
National Geodetic Vertical Datum (NGVD 29)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NI 8 5.448 2.472
4525 A 2000 5.450 2.474
4525 B 2000 10.843 7.867
4525 C 2000 9.122 6.146
4525 D 2000 10.408 7.432
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8444525 PUBLICATION DATE: 04/21/2003
Name: NUT ISLAND, QUINCY BAY
MASSACHUSETTS
NOAA Chart: 13270 Latitude: 42° 16.8' N
USGS Quad: HULL Longitude: 70° 57.2' 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 (NAVD 88).
NGVD 29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded. NGVD 29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads. NGVD 29 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 NGVD 29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at
National Geodetic Survey.
NAVD 88 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. NAVD 88 replaces NGVD 29 as the national
standard geodetic reference for heights. Bench mark elevations relative to
NAVD 88 are available from NGS through the World Wide Web at
National Geodetic Survey.
NGVD 29 and NAVD 88 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 NAVD 88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD 88 elevations.
The NAVD 88 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, NAVD 88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD 88 elevations listed for
each bench mark in the NGS database.