U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 8417087 PUBLICATION DATE: 02/10/2016
Name: PHIPPS PT. HOCKOMOCK BAY
ME
NOAA Chart: 13296 Latitude: 43° 53.9' N ( 43.89830)
USGS Quad: Westport Longitude: 69° 44.6' W ( -69.74330)
To reach the tidal bench marks from the intersection of US Highway 1 (Bath Road)
and State Highway 144 (Old Ferry Road) in Wiscasset, proceed SW on US Highway 1
for 1.7 km (1.1 mi) to Montsweag Road on the left, turn left and proceed 3.7 km
(2.3 mi) south on Montsweag Road to a slight left at the intersection with
Murphy's Corner Road where the road becomes Phipps Point Road, continue 2.4 km
(1.5 mi) south on Phipps Point Road to a driveway on the right leading to the
residence at 315 Phipps Point Road, turn right and proceed 140 m (460 ft) SW on
the driveway to the residence, then continue by vehicle, if conditions permit,
or on foot 0.8 km (0.5 mi) south on a two track road located to the west of the
residence to its termination at Phipps Point. The bench marks are located in
bedrock along the two track between the residence and Phipps Point. The station
is located on a private pier at Phipps Point.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7087 A 2015
DESIGNATION: 841 7087 A
MONUMENTATION: DB VM#: 21475
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: In rock outcrop OPUS PID#: BBDV80
LATITUDE: 43° 54.0' N ( 43.90050) LONGITUDE: 69° 44.5' W ( -69.74208)
The primary bench mark is a disk set in bedrock, 52.53 m (172.3 ft) NNE of a 4
ft (1.2 m) by 4 ft (1.2 m) lone boulder in a field, 46.20 m (151.6 ft) NNW of
the highest point of a bedrock outcrop E of the two track, 35.40 m (116.1 ft) E
of the approximate center of a grove of four white pine trees, 12.8 m (42.0 ft)
W of the W edge of the two track, 1.03 m (3.4 ft) ENE of the highest point on
the bedrock outcrop and about 1.3 m (4.3 ft) higher than the two track grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 8417087 PUBLICATION DATE: 02/10/2016
Name: PHIPPS PT. HOCKOMOCK BAY
ME
NOAA Chart: 13296 Latitude: 43° 53.9' N ( 43.89830)
USGS Quad: Westport Longitude: 69° 44.6' W ( -69.74330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 1 1943
DESIGNATION: TIDAL 1
MONUMENTATION: DJ VM#: 21476
AGENCY: US Coast & Geodetic Survey IDB PID#: OB0181
SETTING CLASSIFICATION: In rock outcrop OPUS PID:
LATITUDE: 43° 53.9' N ( 43.89861) LONGITUDE: 69° 44.5' W ( -69.74214)
The bench mark is a disk set in a bedrock outcrop, 24.40 m (80.1 ft) S of the SE
corner of a 0.88 m (2.9 ft) by 2.38 m (7.8 ft) shed, 23.32 m (76.5 ft) ESE of a
ship mast which is now a flagpole, 11.96 m (39.2 ft) E of the SE corner of a
Phipps Point historical plaque set on a boulder, 9.55 m (31.3 ft) ESE of a 35
inch (89 cm) diameter tree, 0.20 m (0.7 ft) ESE of the highest point of the
bedrock outcrop and about 0.80 m (2.6 ft) higher than the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8417087 PUBLICATION DATE: 02/10/2016
Name: PHIPPS PT. HOCKOMOCK BAY
ME
NOAA Chart: 13296 Latitude: 43° 53.9' N ( 43.89830)
USGS Quad: Westport Longitude: 69° 44.6' W ( -69.74330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1943
DESIGNATION: TIDAL 3
MONUMENTATION: DJ VM#: 21477
AGENCY: US Coast & Geodetic Survey IDB PID#: OB0183
SETTING CLASSIFICATION: Abutments and piers of large bridges OPUS PID:
LATITUDE: 43° 53.9' N ( 43.89833) LONGITUDE: 69° 44.5' W ( -69.74222)
The bench mark is disk set in a concrete abutment to a pier set on bedrock,
39.19 m (128.6 ft) SSE of a flagpole made of a ship mast, 30.80 m (101.0 ft) SSE
of a Phipps Point historical plaque set on a boulder, 13.90 m (45.6 ft) SSW of
the S most tree at Phipps Point, 2.39 m (7.8 ft) SSW of the NW corner of the
concrete ramp leading to the pier and about 0.19 m (0.6 ft) lower than the pier
decking.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8417087 PUBLICATION DATE: 02/10/2016
Name: PHIPPS PT. HOCKOMOCK BAY
ME
NOAA Chart: 13296 Latitude: 43° 53.9' N ( 43.89830)
USGS Quad: Westport Longitude: 69° 44.6' W ( -69.74330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: N 156 1963
DESIGNATION: N 156
MONUMENTATION: DB VM#: 21478
AGENCY: US Coast & Geodetic Survey IDB PID#: OB0180
SETTING CLASSIFICATION: In rock outcrop OPUS PID:
LATITUDE: 43° 54.2' N ( 43.90358) LONGITUDE: 69° 44.5' W ( -69.74092)
The bench mark is a disk set in a bedrock outcrop, 42.15 m (138.3 ft) SSW of the
SW corner of a stone wall on the W side of the two track, 34.60 m (113.5 ft) ENE
of a 40 inch (102 cm) diameter white pine tree, 32.05 m (105.2 ft) WSW of the SW
corner of the main house, 17.09 m (56.1 ft) WSW of a intake to a culvert on the
E side of the two track, 12.55 m (41.2 ft) W of the W edge of the two track,
0.18 m (0.6 ft) SW of the highest point on the bedrock outcrop and about 0.17 m
(0.6 ft) higher than the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8417087 PUBLICATION DATE: 02/10/2016
Name: PHIPPS PT. HOCKOMOCK BAY
ME
NOAA Chart: 13296 Latitude: 43° 53.9' N ( 43.89830)
USGS Quad: Westport Longitude: 69° 44.6' W ( -69.74330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 2 1943
DESIGNATION: TIDAL 2
MONUMENTATION: DJ VM#: 21479
AGENCY: US Coast & Geodetic Survey IDB PID#: OB0182
SETTING CLASSIFICATION: In rock outcrop OPUS PID:
LATITUDE: 43° 53.9' N ( 43.89847) LONGITUDE: 69° 44.5' W ( -69.74217)
The bench mark is a disk set in a bedrock outcrop, 20.62 m (67.7 ft) W of the SE
corner of a historical plaque for Phipps Point set on a boulder, 10.60 m (34.8
ft) N of the N edge of a concrete ramp leading to a pier. And 1.67 m (5.5 ft) W
of the S tree at Phipps Point.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8417087 PUBLICATION DATE: 02/10/2016
Name: PHIPPS PT. HOCKOMOCK BAY
ME
NOAA Chart: 13296 Latitude: 43° 53.9' N ( 43.89830)
USGS Quad: Westport Longitude: 69° 44.6' W ( -69.74330)
T I D A L D A T U M S
Tidal datums at PHIPPS PT. HOCKOMOCK BAY based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: May 2015 - August 2015
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8418150 PORTLAND, CASCO BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 3.002
MEAN HIGH WATER MHW = 2.874
North American Vertical Datum NAVD88 = 1.515
MEAN SEA LEVEL MSL = 1.511
MEAN TIDE LEVEL MTL = 1.487
MEAN LOW WATER MLW = 0.101
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7087 A 2015 15.228 12.354
NO 1 1943 5.439 2.565
NO 3 1943 4.013 1.139
N 156 1963 23.755 20.881
NO 2 1943 4.535 1.661
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8417087 PUBLICATION DATE: 02/10/2016
Name: PHIPPS PT. HOCKOMOCK BAY
ME
NOAA Chart: 13296 Latitude: 43° 53.9' N ( 43.89830)
USGS Quad: Westport Longitude: 69° 44.6' W ( -69.74330)
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.