U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
Station ID: 8720625 PUBLICATION DATE: 04/27/2020
Name: RACY POINT, ST JOHNS RIVER
FL
NOAA Chart: 11492 Latitude: 29° 48.1' N ( 29.80170)
USGS Quad: RIVERDALE Longitude: 81° 32.9' W ( -81.54830)
To reach the tidal bench marks from the junction of County Road C-13 and State
Road 207 north of Hastings, proceed north on County Road C-13 for 11.3 km (7.0
mi) to the residence at No. 1635 County Road C-13. The bench marks are in the
vicinity of several residences in the immediate area of Racy Point. The tide
gage was located on a navigation structure about 79 m (260 ft) south of the
bulkhead along the St. Johns River. The gage site can only be reached by boat
from the nearby Racy Point Park boat ramp.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 0625 A 1995
DESIGNATION: 872 0625 A TIDAL
MONUMENTATION: Flange-encased Rod VM#: 13494
AGENCY: National Ocean Service (NOS) IDB PID#: DM1498
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 48.1' N ( 29.80089) LONGITUDE: 81° 33.0' W ( -81.54936)
The primary bench mark is a flange-encased rod located near the shoreline at
Racy Point, 91.44 m (300.0 ft) SW of the centerline of County Road C-13, 23.96 m
(78.6 ft) SSE of the SE corner of the residence No. 1635 (Franklin), 4.27 m
(14.0 ft) north of the sea wall, and 3.29 m (10.8 ft) NW of a 42-inch palm tree.
The datum point is set 15.2 cm (0.5 ft) below the level of the NGS logo cap,
being the top of a stainless steel rod driven 19.81 m (65 ft) to refusal,
encased in a 5-inch NGS logo cap flush with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 8720625 PUBLICATION DATE: 04/27/2020
Name: RACY POINT, ST JOHNS RIVER
FL
NOAA Chart: 11492 Latitude: 29° 48.1' N ( 29.80170)
USGS Quad: RIVERDALE Longitude: 81° 32.9' W ( -81.54830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0625 B 1995
DESIGNATION: 872 0625 B TIDAL
MONUMENTATION: Flange-encased Rod VM#: 13495
AGENCY: National Ocean Service (NOS) IDB PID#: DM1497
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 48.1' N ( 29.80092) LONGITUDE: 81° 33.0' W ( -81.54983)
The bench mark is a flange-encased rod located along the shoreline at Racy
Point, 91.44 m (300.0 ft)SW of the centerline of County Road C-13, 27.83 m (91.3
ft) SW of the SW corner of residence No. 1635 (Franklin), 23.77 m (78.0 ft)
south of the SE corner of the next house to the west (Floyd), and 5.12 m (16.8
ft) north of the sea wall. The datum point is set 6.1 cm (0.2 ft) below the
level of the NGS logo cap, being the top of a stainless steel rod driven 19.50 m
(64 ft) to refusal, encased in a 5-inch NGS logo cap flush with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 8720625 PUBLICATION DATE: 04/27/2020
Name: RACY POINT, ST JOHNS RIVER
FL
NOAA Chart: 11492 Latitude: 29° 48.1' N ( 29.80170)
USGS Quad: RIVERDALE Longitude: 81° 32.9' W ( -81.54830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: STJ 9
DESIGNATION: STJ 9
MONUMENTATION: Bench Mark disk VM#: 13497
AGENCY: Florida Department of Transportation
(FLDT) IDB PID#: AQ2628
SETTING CLASSIFICATION: Bridge railing OPUS PID:
LATITUDE: 29° 48.0' N ( 29.79936) LONGITUDE: 81° 32.4' W ( -81.53964)
The bench mark is a disk set in the bridge guardrail at the NE corner of the
Racy Point Bridge, located 10.16 km (6.35 mi) north along County Road C-13 from
its intersection with State Road 207 north of Hastings, 6.49 m (21.3 ft) NNE of
the centerline of County Road C-13, and 0.91 m (3.0 ft) above the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 8720625 PUBLICATION DATE: 04/27/2020
Name: RACY POINT, ST JOHNS RIVER
FL
NOAA Chart: 11492 Latitude: 29° 48.1' N ( 29.80170)
USGS Quad: RIVERDALE Longitude: 81° 32.9' W ( -81.54830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: RIVERDALE 2 1950
DESIGNATION: RIVERDALE 2
MONUMENTATION: Triangulation Station disk VM#: 13498
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AQ2407
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 48.1' N ( 29.80192) LONGITUDE: 81° 33.0' W ( -81.54981)
The bench mark is a disk set in top of a 8-inch square concrete monument located
on the line between the Floyds and Ellithorp properties at Racy Point, 46.63 m
(153.0 ft) NE of the garage on the Floyds' property, 9.45 m (31.0 ft) west of
the centerline of County Road C-13, 4.88 m (16.0 ft) east of a 16-inch oak tree,
0.61 m (2.0 ft) west of a 4-inch square concrete witness post standing 0.46 m
(1.5 ft) high, and 0.09 cm (0.3 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 8720625 PUBLICATION DATE: 04/27/2020
Name: RACY POINT, ST JOHNS RIVER
FL
NOAA Chart: 11492 Latitude: 29° 48.1' N ( 29.80170)
USGS Quad: RIVERDALE Longitude: 81° 32.9' W ( -81.54830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: RIVERDALE 1933 AZIMUTH
DESIGNATION: RIVERDALE AZ MK
MONUMENTATION: Azimuth Mark disk VM#: 13499
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AE6506
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 48.0' N ( 29.80072) LONGITUDE: 81° 32.8' W ( -81.54703)
The bench mark is a disk set in top of a concrete monument near the shoreline at
Racy Point, 11.43 m (37.5 ft) south of the centerline of County Road C-13, 6.10
m (20.0 ft) north of the river bank, 0.61 m (2.0 ft) south of a 0.12 m (0.4 ft)
square concrete witness post standing 0.46 m (1.5 ft) high, and 0.15 m (0.5 ft)
above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 8720625 PUBLICATION DATE: 04/27/2020
Name: RACY POINT, ST JOHNS RIVER
FL
NOAA Chart: 11492 Latitude: 29° 48.1' N ( 29.80170)
USGS Quad: RIVERDALE Longitude: 81° 32.9' W ( -81.54830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: RIVERDALE RM 2 1933
DESIGNATION: RIVERDALE RM 2
MONUMENTATION: Reference Mark disk VM#: 13500
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AE6507
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 48.1' N ( 29.80161) LONGITUDE: 81° 33.0' W ( -81.55003)
The mark is located 85.3 m (279.9 ft) W of the centerline of County Road 13,
29.5 m (96.8 ft) E of a concrete seawall, 21.2 m (69.6 ft) E of a square shed
and 0.2 m (0.7 ft) E of the NE corner of a 22 x 34 ft wooden garage. The bench
mark is a disk set at the NE corner of a garage, set in top of a concrete
monument projecting 0.1 m (0.4 ft) above the level of the ground.
BENCH MARK STAMPING: 0625 C 2006
DESIGNATION: 872 0625 C TIDAL
MONUMENTATION: Flange-encased Rod VM#: 20984
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: DI9226
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: DI9226
LATITUDE: 29° 48.3' N ( 29.80438) LONGITUDE: 81° 33.0' W ( -81.55043)
The bench mark is a stainless steel rod located 13.3 m (43.5 ft) SW of a mailbox
at 1510, 8.0 m (26.5 ft) WNW of the centerline of County Road C-13, 5.0 m (16.5
ft) WNW of the edge of the pavement of County Road C-13 and 1.2 m (4.0 ft) east
of the riverbank, driven to refusal at a depth of 9.7 m (31.8 ft) with a NGS
logo cap flush with the ground and about 0.45 m (1.5 ft) below the level of
County Road C-13, the datum point is recessed 0.3 ft below the level of the NGS
logo cap. Note: A magnet was placed inside of the NGS logo cap and access to
the datum point is had through a 5-inch NGS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 8720625 PUBLICATION DATE: 04/27/2020
Name: RACY POINT, ST JOHNS RIVER
FL
NOAA Chart: 11492 Latitude: 29° 48.1' N ( 29.80170)
USGS Quad: RIVERDALE Longitude: 81° 32.9' W ( -81.54830)
T I D A L D A T U M S
Tidal datums at RACY POINT, ST JOHNS RIVER based on:
LENGTH OF SERIES: 4 YEARS
TIME PERIOD: 5/14-4/16, 4/17-3/19
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8720226 SOUTHBANK RIVERWALK, ST JOHNS RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/07/2016) = 1.738
MEAN HIGHER HIGH WATER MHHW = 0.385
MEAN HIGH WATER MHW = 0.367
MEAN TIDE LEVEL MTL = 0.194
MEAN SEA LEVEL MSL = 0.194
North American Vertical Datum NAVD88 = 0.189
MEAN LOW WATER MLW = 0.022
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (04/15/2004) = -0.380
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
0625 A 1995 1.988 1.621
0625 B 1995 1.314 0.947
STJ 9 3.258 2.891
RIVERDALE 2 1950 2.764 2.397
RIVERDALE 1933 AZIMUTH 3.452 3.085
RIVERDALE RM 2 1933 2.636 2.269
0625 C 2006 1.504 1.137
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 8720625 PUBLICATION DATE: 04/27/2020
Name: RACY POINT, ST JOHNS RIVER
FL
NOAA Chart: 11492 Latitude: 29° 48.1' N ( 29.80170)
USGS Quad: RIVERDALE Longitude: 81° 32.9' W ( -81.54830)
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.