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National Ocean Service
Datums Page Page 1 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
To reach the bench marks from the St. Johns River Ferry landing at the
Intersection of Broad Street and Ocean Street in Mayport, go northeast on Ocean
Street for 0.24 km (0.15 mile) to the entrance to St. Johns Bar Pilot
Association and the marks are in the vicinity. The tide gage was installed on
the west end of the Pilot Association dock.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 0218 A 1995
DESIGNATION: 872 0218 A TIDAL
MONUMENTATION: Flange-encased Rod VM#: 13512
AGENCY: National Ocean Service (NOS) IDB PID#: DI9221
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: DI9221
LATITUDE: 30° 23.8' N ( 30.39739) LONGITUDE: 81° 25.7' W ( -81.42758)
The primary bench mark is a flange encased rod, located near the entrance to the
Saint Johns Bar Pilot Association, 140.97 m (462.5 ft) north of the approximate
center of Ocean Street (State Highway AIA), 66.60 m (218.5 ft) west of the
center of the Pilot Association Dock, 66.45 m (218.0 ft) SW of the Pilot
Association Building, 37.37 m (122.6 ft) west of the NW corner of the Pilot
Association Club, 19.20 m (63.0 ft) NNW of a power pole with two lights on the
top and 0.30 m (1.0 ft) SW of the NW end of a 1.83 m (6.0 ft) tall chainlink
fence line. The datum point is the top of a stainless steel rod driven 21 m (68
ft) to refusal, recessed 0.09 m (0.3 ft) below the level of the logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0218 B 1995
DESIGNATION: 872 0218 B
MONUMENTATION: Flange-encased Rod VM#: 13513
AGENCY: National Ocean Service (NOS) IDB PID#: DL5746
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 23.8' N ( 30.39639) LONGITUDE: 81° 25.6' W ( -81.42706)
The bench mark is a flange encased rod located near the left side of the the
entrance to the Saint Johns Bar Pilot Association, 47.12 m (154.6 ft) east of
the edge of Mayport City Park entrance, 15.39 m (50.5 ft) north of the
approximate centerline of Ocean Street (State Highway AIA), 10.27 m (33.7 ft)
WSW of the St. Johns Bar Pilot Association entrance gate, 5.03 m (16.5 ft)
north of the south end of a 1.83 m (6.0 ft) tall chainlink fence line and 0.40 m
(1.3 ft) west of a 1.83 m (6.0 ft) tall chainlink fence line. The datum point
is the top of a stainless steel rod driven 23 m (75 ft) to refusal, and recessed
0.09 m (0.3 ft) below the level of the logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: JAX PILOT 1982 JAX FLA
DESIGNATION: JAX PILOT
MONUMENTATION: Bench Mark disk VM#: 13515
AGENCY: US Army Corps of Engineers (USE) IDB PID#: DL5747
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 30° 23.9' N ( 30.39778) LONGITUDE: 81° 25.6' W ( -81.42708)
The bench mark is a disk set in the center of the Pilot Association Dock, 25.48
m (83.6 ft) north of the NE corner of the Pilot Association Club Building, 7.13
m (23.4 ft) west of the east end of a wall, and 4.82 m (15.8 ft) east of the
west end of the sea wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: J 324 RESET 1971
DESIGNATION: J 324 RESET
MONUMENTATION: Bench Mark disk VM#: 13516
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: BC0463
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 30° 23.8' N ( 30.39617) LONGITUDE: 81° 25.6' W ( -81.42689)
The bench mark is a disk set in the top of a round concrete monument near the
entrance to the St Johns Bar Pilot Association , 22.86 m (75.0 ft) south of the
center of the guard gate, 3.05 m (10.0 ft) west of the approximate center of a
paved road, 0.46 m (1.5 ft) south of a metal witness post, 0.30 m (1.0 ft) east
of a 1.83 m (6.0 ft) tall chainlink fence, and projecting about 18.3 cm (0.6 ft)
above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Mayport 2 RM NO 1 1946
DESIGNATION: Mayport 2 RM 1
MONUMENTATION: Bench Mark disk VM#: 19714
AGENCY: U.S.A corp of engineers IDB PID#: BC0459
SETTING CLASSIFICATION: Concrete pipe OPUS PID:
LATITUDE: 30° 23.6' N ( 30.39333) LONGITUDE: 81° 25.9' W ( -81.43106)
The bench mark is a disk set in a 4-inch concrete filled pipe near a warehouse,
21.61 m (70.89 ft) ESE of the SE corner of the office, 16.00 m (52.49 ft) east
of a flag pole, 2.41 m (7.90 ft) SSE of the SW corner of a warehouse, 0.40 m
(1.31 ft) SE of the NE corner of a 1 M X 2 M (3.28 ft x 6.56 ft) concrete block,
and 0.15 m (0.49 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1942 B.M. M.S.L. E.D.M. 14
DESIGNATION: EDM 14
MONUMENTATION: Bench Mark disk VM#: 19715
AGENCY: U.S.A corp of engineers IDB PID#: BC0467
SETTING CLASSIFICATION: Concrete block OPUS PID:
LATITUDE: 30° 23.6' N ( 30.39319) LONGITUDE: 81° 25.9' W ( -81.43153)
The bench mark is a disk set in the top of a concrete block near a garage, 20.79
m (68.21 ft) SW of the SE corner of the office building, 17.80 m (58.40 ft) WSW
of a flag pole, 3.20 m (10.50 ft) NNW of the NW corner of the garage, 0.50 m
(1.64 ft) NE of a witness post, and 0.09 m (0.30 ft) below ground level.
BENCH MARK STAMPING: 12 7.861
DESIGNATION: 872 0220 TIDAL 12
MONUMENTATION: Tidal Station disk VM#: 19716
AGENCY: U.S coast and Geodetic survey IDB PID#: BC0461
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 30° 23.7' N ( 30.39442) LONGITUDE: 81° 25.8' W ( -81.42967)
The bench mark is a disk set in a concrete retaining wall, 28.90 m (94.82 ft) SE
of the centerline of Ocean street, 17.50 m (57.41 ft) east of utility pole no.
20, 6.61 m (21.69 ft) NW of the SE end of the retaining wall, 5.61 m (18.41 ft)
NE of the centerline of Palmer street, 5.79 m (19.00 ft) SSW of utility pole no.
146, 0.21 m (0.69 ft) SW of a witness post, and 0.49 m (1.61 ft) above the level
of Palmer street.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0220 A 1978
DESIGNATION: 872 0220 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 19717
AGENCY: National Ocean Survey/Service (NOS) IDB PID#: BC2486
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BC2486
LATITUDE: 30° 23.6' N ( 30.39328) LONGITUDE: 81° 25.9' W ( -81.43136)
The bench mark is a disk located 13.32 m (43.70 ft) south of the south corner of
the office, 13 m (42.7 ft) west of the west corner of the warehouse, and 2.68 m
(8.79 ft) SE of a flagpole. The bench mark is crimped to a stainless steel rod
driven an unspecified depth to refusal, and encased in a 4-inch PVC pipe and
concrete kickblock.
BENCH MARK STAMPING:
DESIGNATION: 872 0220 NO STAMPING 1
MONUMENTATION: See descriptive text VM#: 19869
AGENCY: IDB PID:
SETTING CLASSIFICATION: Pipe cap OPUS PID:
LATITUDE: 30° 23.6' N ( 30.39322) LONGITUDE: 81° 25.9' W ( -81.43092)
The bench mark is an iron cap riveted on top of a 1-inch galvanized iron pipe,
14 m (45.9 ft) west of the centerline of Ocean Street, 10.36 m (33.99 ft) SSW of
a fence corner in the NE corner of the grounds, and 0.91 m (2.99 ft) SE of the
NE corner of the warehouse and set 0.46 m (1.51 ft) below ground level, encased
by a 6-inch PVC pipe projecting 0.30 m (0.98 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: EDM 13 1942
DESIGNATION: EDM 13
MONUMENTATION: Survey disk VM#: 19870
AGENCY: United States Army Corps of Engineers IDB PID#: DL5704
SETTING CLASSIFICATION: Concrete post imbedded in the ground OPUS PID:
LATITUDE: 30° 23.6' N ( 30.39328) LONGITUDE: 81° 25.9' W ( -81.43122)
The bench mark is set atop a pipe on the west side of the warehouse, 5.33 m
(17.49 ft) SW of the NW corner of the warehouse, 1.37 m (4.49 ft) west of its
west wall, 0.46 m (1.51 ft) WSW of bench mark Mayport 2 RM NO 1, and 0.15 m
(0.49 ft) south of a concrete slab inside a wooden fenced area used for garbage
can storage.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: B 407 1991
DESIGNATION: B 407
MONUMENTATION: Flange-encased Rod VM#: 19871
AGENCY: IDB PID#: BC2546
SETTING CLASSIFICATION: Flange-Encased Rod OPUS PID:
LATITUDE: 30° 23.6' N ( 30.39303) LONGITUDE: 81° 25.9' W ( -81.43153)
The bench mark is the top of a stainless steel rod, 38.9 m (127.6 ft) SW of the
SW corner of the ferry maintenance office, 22.6 m (74.1 ft) NW of a chain-link
fence, 18.2 m (59.7 ft) SE of the SE face of a retaining wall, 9.5 m (31.2 ft)
SW of the west corner of a garage, and 0.9 m (3.0 ft) NE of a chain-link fence,
driven 20.4 m (66.9 ft) to refusal and encased in a 5-inch NGS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 10 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BM E.D.M. 15 MSL 1942
DESIGNATION: EDM 15
MONUMENTATION: Survey disk VM#: 20651
AGENCY: U.S. Army Corp of Engineers (USE) IDB PID#: BC0458
SETTING CLASSIFICATION: Step OPUS PID:
LATITUDE: 30° 23.6' N ( 30.39281) LONGITUDE: 81° 25.8' W ( -81.42919)
The bench mark is set near the SW end of the bottom step at the SE entrance to a
house at the ferry maintenance facility (4610 Ocean Street), 57.30 m (187.99 ft)
SE of the SE corner of the ferry maintenance office, 23.29 m (76.41 ft) SW of
the center of an entrance road and gate, and 14 m (45.9 ft) NW of the center of
Ocean Street.
BENCH MARK STAMPING: 0218 D 2016
DESIGNATION: 872 0218 D
MONUMENTATION: Bench Mark disk VM#: 21862
AGENCY: NOS IDB PID:
SETTING CLASSIFICATION: Concrete bulkhead OPUS PID:
LATITUDE: 30° 23.8' N ( 30.39608) LONGITUDE: 81° 25.8' W ( -81.42961)
The bench mark is located north of the cul de sac of St Johns River ferry, on
the seawall behind the Morningstar Marina building, 51.00 m (167.3 ft) NW of the
NW corner of Morningstar Marina, 42.2 m (138.5 ft) NE of east face of pier, 3.54
m (11.6 ft) south of north face of seawall, and .340 m (1.1 ft) east of the west
face of seawall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 11 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
T I D A L D A T U M S
Tidal datums at BAR PILOTS DOCK, ST JOHNS RIVER based on:
LENGTH OF SERIES: 16 YEARS
TIME PERIOD: 1/01-12/10, 1/12-12/14, 1/16-12/18
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8720030 FERNANDINA BEACH, AMELIA RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/07/2016) = 2.488
MEAN HIGHER HIGH WATER MHHW = 1.511
MEAN HIGH WATER MHW = 1.429
North American Vertical Datum NAVD88 = 0.911
MEAN SEA LEVEL MSL = 0.752
MEAN TIDE LEVEL MTL = 0.738
MEAN LOW WATER MLW = 0.047
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (03/08/2008) = -0.777
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
0218 A 1995 2.233 0.804
0218 B 1995 3.600 2.171
JAX PILOT 1982 JAX FLA 2.846 1.417
J 324 RESET 1971 4.096 2.667
Mayport 2 RM NO 1 1946 2.160 0.731
1942 B.M. M.S.L. E.D.M. 14 1.953 0.524
12 7.861 2.957 1.528
0220 A 1978 2.147 0.718
872 0220 NO STAMPING 1 1.833 0.404
EDM 13 1942 2.094 0.665
B 407 1991 1.953 0.524
BM E.D.M. 15 MSL 1942 2.650 1.221
0218 D 2016 2.587 1.158
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 12 of 12
Station ID: 8720218 PUBLICATION DATE: 12/15/2020
Name: BAR PILOTS DOCK, ST JOHNS RIVER
FL
NOAA Chart: 11490 Latitude: 30° 23.9' N ( 30.39817)
USGS Quad: MAYPORT Longitude: 81° 25.7' W ( -81.42789)
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.