U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8448248 PUBLICATION DATE: 01/07/2011
Name: PENIKESE ISLAND
MA
NOAA Chart: 13230 Latitude: 41° 27.0' N ( 41.45000)
USGS Quad: CUTTYHUNK CUTTYHUNK Longitude: 70° 55.3' W ( -70.92170)
To reach the tidal bench marks from Cuttyhunk Harbor, proceed by boat north for
approximately 2.4 km (1.5 mi) to a cove on the south side of Penikese Island.
The bench marks are located on the west side of the cove near the Penikese
schoolhouse. The tide gage and staff were also located on the west shore of the
cove.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1976
DESIGNATION: 844 8248 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 2090
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Granite rock OPUS PID:
LATITUDE: 41° 27.0' N ( 41.44944) LONGITUDE: 70° 55.3' W ( -70.92139)
The primary bench mark is a disk set in a granite rock halfway between the
approximate high water mark and a grassy plateau, 150 m (492 ft) east of the NE
edge of the Penikese school house, 30 m (98 ft) west of the tip of a rock jetty,
and 1 m (3 ft) from the ridge overlooking the beach.
BENCH MARK STAMPING: NO 3 1976
DESIGNATION: 844 8248 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 2092
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete pad OPUS PID:
LATITUDE: 41° 27.0' N ( 41.44944) LONGITUDE: 77° 55.3' W ( -77.92139)
The bench mark is set in the center of a 7 m x 3 m (23 ft x 10 ft) concrete slab
which is west of the open foundation and 15 m (49 ft) south of the SW corner of
the school house.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8448248 PUBLICATION DATE: 01/07/2011
Name: PENIKESE ISLAND
MA
NOAA Chart: 13230 Latitude: 41° 27.0' N ( 41.45000)
USGS Quad: CUTTYHUNK CUTTYHUNK Longitude: 70° 55.3' W ( -70.92170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 6 1933
DESIGNATION: 844 8248 TIDAL 6
MONUMENTATION: Tidal Station disk VM#: 19816
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Cistern OPUS PID:
LATITUDE: 44° 27.0' N ( 44.44944) LONGITUDE: 77° 55.3' W ( -77.92139)
The bench mark is set in the top of the easter quarter of a 3.2 m (10.5 ft)
square cistern located 19.05 m (62.5 ft) from the SE corner of the Penikese
Island school house, and 15 m (49 ft) NE of a large mapel tree which is 23 m (76
ft) south of the school house.
BENCH MARK STAMPING: NO 7 1993
DESIGNATION: 844 8248 TIDAL 7
MONUMENTATION: Tidal Station disk VM#: 19817
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Flagpole base OPUS PID:
LATITUDE: 41° 27.0' N ( 41.44944) LONGITUDE: 77° 55.3' W ( -77.92139)
The bench mark is set in the western half of an old 2 m (5 ft) diameter
concrete flagpole base, 17.12 m (56.5 ft) east from the SE corner of the
southern end of the sidewalk leading from the woodshop and 16 m (53 ft) ENE from
the SE corner of the woodshop at the Penikese Island School.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8448248 PUBLICATION DATE: 01/07/2011
Name: PENIKESE ISLAND
MA
NOAA Chart: 13230 Latitude: 41° 27.0' N ( 41.45000)
USGS Quad: CUTTYHUNK CUTTYHUNK Longitude: 70° 55.3' W ( -70.92170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 8 1993
DESIGNATION: 844 8248 TIDAL 8
MONUMENTATION: Tidal Station disk VM#: 19818
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 41° 27.0' N ( 41.44944) LONGITUDE: 77° 55.3' W ( -77.92139)
The bench mark is set in rock outcropping overlooking the island pier, 36.58 m
(120 ft) NW from the NW end of the southern stone wall leading to the pier and
8.08 m (26.5 ft) SE of the SE corner of the Penikese Island boat shed.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8448248 PUBLICATION DATE: 01/07/2011
Name: PENIKESE ISLAND
MA
NOAA Chart: 13230 Latitude: 41° 27.0' N ( 41.45000)
USGS Quad: CUTTYHUNK CUTTYHUNK Longitude: 70° 55.3' W ( -70.92170)
T I D A L D A T U M S
Tidal datums at PENIKESE ISLAND based on:
LENGTH OF SERIES: 7 MONTHS
TIME PERIOD: April 1993 - October 1993
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8452660 NEWPORT, NARRAGANSETT BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.157
MEAN HIGH WATER MHW = 1.082
MEAN TIDE LEVEL MTL = 0.562
MEAN SEA LEVEL MSL = 0.513
MEAN LOW WATER MLW = 0.041
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 1 1976 2.215 1.133
NO 3 1976 7.299 6.217
NO 6 1933 3.755 2.673
NO 7 1993 5.976 4.894
NO 8 1993 4.292 3.210
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8448248 PUBLICATION DATE: 01/07/2011
Name: PENIKESE ISLAND
MA
NOAA Chart: 13230 Latitude: 41° 27.0' N ( 41.45000)
USGS Quad: CUTTYHUNK CUTTYHUNK Longitude: 70° 55.3' W ( -70.92170)
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.