U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 8727956 PUBLICATION DATE: 06/09/2025
Name: ECONFINA RIVER, INSIDE
FL
NOAA Chart: 11405 Latitude: 30° 3.2' N ( 30.05330)
USGS Quad: SNIPE ISLAND Longitude: 83° 54.6' W ( -83.91000)
THE TEMPORARY BENCH MARK 872 7956 AQUA TRAK IS ABOUT 19.3 MI (31.1 KM)
EAST-SOUTHEAST OF SAINT STATIONS, 18.2 MI (29.3 KM) WEST-SOUTHWEST OF SECOTAN,
15.2 MI (24.5 KM) WEST OF HAMPTON SPRINGS, IN SECTION 11, TOWNSHIP 5 SOUTH,
RANGE 4 EAST. TO REACH THE TEMPORARY BENCH MARK 872 7956 AQUA TRAK FROM THE
INTERSECTION OF U.S. HIGHWAY 98 AND COUNTY ROAD 14 ABOUT 20.2 MI (32.5 KM) WEST
OF PERRY, GO SOUTH ON COUNTY ROAD 14 (ECONFINE RIVER ROAD) FOR 5.8 MI (9.3 KM)
TO THE JUNCTION OF SEMINOLE LANE ON THE LEFT. CONTINUE SOUTH ON COUNTY ROAD 14
(ECONFINE RIVER ROAD) FOR 0.3 MI (0.5 KM) TO THE TEMPORARY BENCH MARK 872 7956
AQUA TRAK ON THE LEFT, ABOUT 30.0 FT (9.1 M) SOUTHEAST OF THE STEP IN THE
SEAWALL. IT IS 126 FT (38.4 M) NORTHEAST OF THE SOUTHEASTERLY CORNER OF THE
EASTERLY MOST DOCK FOR THE BOAT LAUNCH AT ECONFINA STATE PARK., 56 FT (17.1 M)
SOUTH OF THE NORTHERLY MOST END OF A WOOD SEAWALL, AND, 35 FT (10.7 M) SOUTHEAST
OF THE NORTHWESTERLY SHORE LINE OF THE ECONFINA RIVER,.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7956 H 2022
DESIGNATION: 872 7956 H
MONUMENTATION: Flange-encased Rod VM#: 25042
AGENCY: FLDEP IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 30° 3.5' N ( 30.05908) LONGITUDE: 83° 54.4' W ( -83.90636)
The Primary Benchmark is located 28.2m (92.5 ft) east of power pole number
154124, 20.1 m (66.0 ft) SE of a meter pole, 19.0 m (62.2 ft) north of the
center of the top step leading to the water and 11.9 m (39.1 ft) west of the
north end of the seawall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 8727956 PUBLICATION DATE: 06/09/2025
Name: ECONFINA RIVER, INSIDE
FL
NOAA Chart: 11405 Latitude: 30° 3.2' N ( 30.05330)
USGS Quad: SNIPE ISLAND Longitude: 83° 54.6' W ( -83.91000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7956 E 1977
DESIGNATION: 872 7956 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 8263
AGENCY: Florida Department of Natural Resources
(FLDNR) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 30° 3.3' N ( 30.05500) LONGITUDE: 83° 54.4' W ( -83.90670)
The bench mark is a disk set in the top of a concrete monument, 78 m (255 ft)
ENE of bench mark 7956 D 1977, 11.61 m (38.1 ft) WSW of a powerline pole, 11.37
m (37.3 ft) SSE of the centerline of a dirt road, 0.15 m (0.5 ft) NNW of a metal
witness post, and at ground level.
BENCH MARK STAMPING: 7956 G 2022
DESIGNATION: 872 7956 G
MONUMENTATION: Flange-encased Rod VM#: 25043
AGENCY: FLDEP IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 30° 3.6' N ( 30.05986) LONGITUDE: 83° 54.4' W ( -83.90706)
The benchmark is located 33.5 m (110.0 ft) NW of the NW corner of a wooden
privacy fence, 11.7 m (38.4 ft) east of the park access road and 8.4 m (27.6 ft)
west of the park access road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8727956 PUBLICATION DATE: 06/09/2025
Name: ECONFINA RIVER, INSIDE
FL
NOAA Chart: 11405 Latitude: 30° 3.2' N ( 30.05330)
USGS Quad: SNIPE ISLAND Longitude: 83° 54.6' W ( -83.91000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7956 F 2022
DESIGNATION: 872 7956 F
MONUMENTATION: Flange-encased Rod VM#: 25046
AGENCY: FLDEP IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 30° 3.8' N ( 30.06330) LONGITUDE: 83° 54.3' W ( -83.90427)
The bench mark is located 13.5 m (44.4 ft) south of powerpole f40721 1, 11.5 m
(37.8 ft) NE of the approximate centerline of the driveway for bull red
charters, 10.5 m (34.6 ft) east of the lime rock lining the driveway and 9.0 m
(29.5 ft) west of the approximate centerline of Econfina River Road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8727956 PUBLICATION DATE: 06/09/2025
Name: ECONFINA RIVER, INSIDE
FL
NOAA Chart: 11405 Latitude: 30° 3.2' N ( 30.05330)
USGS Quad: SNIPE ISLAND Longitude: 83° 54.6' W ( -83.91000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: A 714 2008
DESIGNATION: A 714
MONUMENTATION: Survey disk VM#: 25048
AGENCY: FLDEP IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 30° 4.2' N ( 30.06936) LONGITUDE: 83° 54.1' W ( -83.90200)
The benchmark is located 13.7 m (45.0 ft) west of the approximate centerline of
Econfine River Road, 12.8 m (42.1 ft) NNW of the telephone box, 9.8 m (32.0 ft)
west of the west edge of the pavement of Econfina River Road, 1.8 m (5.8 ft) NW
of 0.6 m (2ft) pine tree and 0.4 m (1.3 ft) east of carsonite witness post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8727956 PUBLICATION DATE: 06/09/2025
Name: ECONFINA RIVER, INSIDE
FL
NOAA Chart: 11405 Latitude: 30° 3.2' N ( 30.05330)
USGS Quad: SNIPE ISLAND Longitude: 83° 54.6' W ( -83.91000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: TAY 38 1985 BSM
DESIGNATION: TAY 38
MONUMENTATION: Survey disk VM#: 25050
AGENCY: FLNDR IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 30° 3.6' N ( 30.06075) LONGITUDE: 83° 53.8' W ( -83.89611)
The benchmark is located 8.07 m (26.5 ft) SE of the centerline of the NW/SE
road, 7.3 m (24 ft) south of the road intersection, 4.4 m (14.5 ft) SW of the
centerline of the NE/SW road, 0.6 m (2 ft) north of a power pole, and 0.3 m (1
ft) NW of a witness post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8727956 PUBLICATION DATE: 06/09/2025
Name: ECONFINA RIVER, INSIDE
FL
NOAA Chart: 11405 Latitude: 30° 3.2' N ( 30.05330)
USGS Quad: SNIPE ISLAND Longitude: 83° 54.6' W ( -83.91000)
T I D A L D A T U M S
Tidal datums at ECONFINA RIVER, INSIDE based on:
LENGTH OF SERIES: 9 MONTHS
TIME PERIOD: May 2022 - January 2023
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8727520 CEDAR KEY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.074
MEAN HIGH WATER MHW = 1.000
North American Vertical Datum NAVD88 = 0.599
MEAN TIDE LEVEL MTL = 0.593
MEAN SEA LEVEL MSL = 0.588
MEAN LOW WATER MLW = 0.185
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7956 H 2022 1.370 0.370
7956 E 1977 1.644 0.644
7956 G 2022 1.647 0.647
7956 F 2022 2.055 1.054
A 714 2008 2.422 1.422
TAY 38 1985 BSM 2.239 1.239
Foot Notes:
Benchmark 7956 E 1977 is based on one differential leveling connection and does
not meet the quality control standards of the NOS. Therefore, caution should be
used when deriving elevation for this marks.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8727956 PUBLICATION DATE: 06/09/2025
Name: ECONFINA RIVER, INSIDE
FL
NOAA Chart: 11405 Latitude: 30° 3.2' N ( 30.05330)
USGS Quad: SNIPE ISLAND Longitude: 83° 54.6' W ( -83.91000)
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.