U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 8414721 PUBLICATION DATE: 04/01/2004 Name: FORT POINT, PENOBSCOT RIVER ME NOAA Chart: 13309 Latitude: 44° 28.3' N ( 44.47170) USGS Quad: CASTINE Longitude: 68° 48.8' W ( -68.81330) To reach the tidal bench marks from the intersection of Main Street and Jellison Point Road in Stockton Springs, proceed south on Jellison Point Road for 4.0 km (2.5 mi) to the entrance to Fort Point State Park, then turn left into the park and follow the entrance road to the first dirt road on the left which leads to a parking area. The bench marks are in the vicinity of the parking area, and along the beach near the pier. The tide gage was located at the NE end of the State Park pier. T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 8414721 PUBLICATION DATE: 04/01/2004 Name: FORT POINT, PENOBSCOT RIVER ME NOAA Chart: 13309 Latitude: 44° 28.3' N ( 44.47170) USGS Quad: CASTINE Longitude: 68° 48.8' W ( -68.81330) T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: NO 30 1948 DESIGNATION: TIDAL 30 STA 30 MONUMENTATION: Tidal Station disk VM#: 13997 AGENCY: US Coast & Geodetic Survey (USC&GS) IDB PID#: PE0381 SETTING CLASSIFICATION: Boulder OPUS PID: LATITUDE: 44° 28.0' N ( 44.46670) LONGITUDE: 68° 48.6' W ( -68.81000) The primary bench mark is a disk set on top of a 2.4 m x1.5 m (8.0 ft x1.5 ft) boulder projecting 1.2 m (4.0 ft) above the level of the ground, about 0.3 km (0.2 mi) along a trail from the lighthouse at Fort Point on Cape Jellison, 110 m (360 ft) SE along the waters edge from the end of the trail leading from the lighthouse to the beach, and near the grass line of a 6.1 m (20.0 ft) bluff.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 8414721 PUBLICATION DATE: 04/01/2004 Name: FORT POINT, PENOBSCOT RIVER ME NOAA Chart: 13309 Latitude: 44° 28.3' N ( 44.47170) USGS Quad: CASTINE Longitude: 68° 48.8' W ( -68.81330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: DESIGNATION: TIDAL 3 STA 30 ALIAS: NO 3 (1908) MONUMENTATION: Drill Hole VM#: 13998 AGENCY: US Coast & Geodetic Survey (USC&GS) IDB PID#: PE0382 SETTING CLASSIFICATION: Boulder OPUS PID: LATITUDE: 44° 28.1' N ( 44.46830) LONGITUDE: 68° 48.6' W ( -68.81000) The bench mark is a drill hole on the top of a 3 m x 2 m (10 ft x 8 ft) boulder projecting 2.1 m (7 ft) above the level of the beach and surrounded by water at high tide, about 274 m (900 ft) NW along the waters' edge from the end of the trail leading to the lighthouse, 165 m (540 ft) NW of bench mark NO 30 1948, 59.4 m (195.0 ft) SE of the inshore end of an old wharf, and 22.9 m (75.0 ft) NW of the north bank of Cape Jellison. BENCH MARK STAMPING: NO. 2 1948 DESIGNATION: 841 4721 NO 2 MONUMENTATION: Tidal Station disk VM#: 13999 AGENCY: US Coast & Geodetic Survey (USC&GS) IDB PID#: PE0383 SETTING CLASSIFICATION: Boulder OPUS PID: LATITUDE: 44° 28.2' N ( 44.47000) LONGITUDE: 68° 48.8' W ( -68.81330) The bench mark is a disk set in top of a 3 m x 3m x 2 m (10 ft x 10 ft x 8 ft) boulder just off the south shoreline, 18.17 m (59.6 ft) SSW of the north corner of the third pier cribbing, 9.06 m (29.7 ft) west of the north corner of the second pier cribbing, and 8.55 m (28.0 ft) south of the north corner of the first cribbing, and approximately 2 m (6 ft) above the beach.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 8414721 PUBLICATION DATE: 04/01/2004 Name: FORT POINT, PENOBSCOT RIVER ME NOAA Chart: 13309 Latitude: 44° 28.3' N ( 44.47170) USGS Quad: CASTINE Longitude: 68° 48.8' W ( -68.81330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4721 A 1998 DESIGNATION: 841 4721 A TIDAL MONUMENTATION: Tidal Station disk VM#: 14000 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Pier foundation OPUS PID#: BBBF06 LATITUDE: 44° 28.3' N ( 44.47170) LONGITUDE: 68° 48.7' W ( -68.81170) The bench mark is a disk set in the NW end of the concrete foundation for the State Park pier, 57.40 m (188.3 ft) SSW of the NNE end of State Park pier, 3.41 m (11.2 ft) WNW of the ESE corner of the pier foundation, and 0.34 m (1.1 ft) east of the west edge of the concrete foundation. BENCH MARK STAMPING: 4721 B 1998 DESIGNATION: 841 4721 B TIDAL MONUMENTATION: Tidal Station disk VM#: 14001 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Boulder OPUS PID: LATITUDE: 44° 28.4' N ( 44.47330) LONGITUDE: 68° 48.7' W ( -68.81170) The bench mark is a disk set in a boulder west of and uphill from the State Park pier, 24.46 m (80.2 ft) south of the north corner of the parking area, 21.21 m (69.6 ft) SSE of the west corner of the parking area, and 19.25 m (63.2 ft) ENE of the northern granite block marking the trail leading to the State Park pier.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 8414721 PUBLICATION DATE: 04/01/2004 Name: FORT POINT, PENOBSCOT RIVER ME NOAA Chart: 13309 Latitude: 44° 28.3' N ( 44.47170) USGS Quad: CASTINE Longitude: 68° 48.8' W ( -68.81330) T I D A L D A T U M S Tidal datums at FORT POINT, PENOBSCOT RIVER based on: LENGTH OF SERIES: 3 MONTHS TIME PERIOD: May 1999 - July 1999 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 = 3.397 MEAN HIGH WATER MHW = 3.276 MEAN SEA LEVEL MSL = 1.710 MEAN TIDE LEVEL MTL = 1.693 MEAN LOW WATER MLW = 0.110 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 30 1948 4.175 0.899 TIDAL 3 STA 30 3.442 0.166 NO. 2 1948 3.448 0.172 4721 A 1998 6.243 2.967 4721 B 1998 13.560 10.284
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 8414721 PUBLICATION DATE: 04/01/2004 Name: FORT POINT, PENOBSCOT RIVER ME NOAA Chart: 13309 Latitude: 44° 28.3' N ( 44.47170) USGS Quad: CASTINE Longitude: 68° 48.8' W ( -68.81330) 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.