U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8729376 PUBLICATION DATE: 07/16/2024
Name: SANTA ROSA HOGTOWN BAYOU
NOAA Chart: 11385 Latitude: 30° 24.0' N ( 30.40000)
USGS Quad: FREEPORT Longitude: 86° 13.7' W ( -86.22830)
To reach the tidal bench marks from the intersection of U.S. Highway 98 and
County Road 393 in Santa Rosa Beach, proceed north on County Road 393 for 2.6 km
(1.6 mi) to the Charles E. Cessna Landing on the south shore of Hogtown Bayou.
The bench marks are in the vicinity of Lions Park and along County Road 393.
Turn left and go northwest on the paved entrance road for about 260 Ft. (79.2m)
to a dock on the right and the Aquatrak.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 9376 G 2016
DESIGNATION: 872 9376 G
MONUMENTATION: Flange-encased Rod VM#: 24358
AGENCY: National Geodetic Survey (NGS) IDB PID#:
SETTING CLASSIFICATION: Stainless Steel Rod OPUS PID#: DQ5788
LATITUDE: 30° 23.9' N ( 30.39842) LONGITUDE: 86° 13.8' W ( -86.22953)
The bench mark is a stainless steel rod located 30.9 m (101.4 ft) west of NOS
mark 9367 A 1977, 13.7 m (45.0 ft) WNW of the approximate centerline of Hogtown
Bayou Lane, 413.1 m (43.0) SSE of a carsonite witness post, 12.6 m (41.3 ft) SE
of the SE corner of a wooden fishing pier, and 3.9 m (12.8 ft) WNW of the NW
edge of a gravel parking lot. The datum point is the top of a stainless steel
rod driven 13.3m (43.7 ft) to refusal and encased in NOS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8729376 PUBLICATION DATE: 07/16/2024
Name: SANTA ROSA HOGTOWN BAYOU
NOAA Chart: 11385 Latitude: 30° 24.0' N ( 30.40000)
USGS Quad: FREEPORT Longitude: 86° 13.7' W ( -86.22830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9376 A 1977
DESIGNATION: 872 9376 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 10101
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete chimmey foundation OPUS PID#: BG3580
LATITUDE: 30° 23.9' N ( 30.39850) LONGITUDE: 86° 13.8' W ( -86.22922)
The bench mark is a disk set in the top of an old chimney foundation, 87 m (285
ft) west of the centerline of County Road 393, 16.00 m (52.5 ft) SE of the SE
corner of the westernmost covered picnic table in Lions Park, 2 m (5 ft) north
of a light pole, and 1.07 m (3.5 ft) above ground level.
BENCH MARK STAMPING: 1 1939
DESIGNATION: 872 9376 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 10103
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 30° 24.0' N ( 30.39975) LONGITUDE: 86° 13.7' W ( -86.22836)
The bench mark is a disk set in the top of a concrete monument, 61 m (200 ft)
north of the bridge over Hogtown Bayou, 12 m (41 ft) east of the centerline of
County Road 393, 27 m (90 ft) south of the SW corner of a wood frame house, and
0.3 m (1 ft) NNW of a 0.40 m (1.3 ft) diameter magnolia tree.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8729376 PUBLICATION DATE: 07/16/2024
Name: SANTA ROSA HOGTOWN BAYOU
NOAA Chart: 11385 Latitude: 30° 24.0' N ( 30.40000)
USGS Quad: FREEPORT Longitude: 86° 13.7' W ( -86.22830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3 1939
DESIGNATION: 872 9376 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 10104
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 30° 24.0' N ( 30.40003) LONGITUDE: 86° 13.7' W ( -86.22789)
The bench mark is a disk set in the top of a concrete monument located at the
east edge of the yard for the first house north of the bridge over Hogtown
Bayou, 51 m (166 ft) east of the centerline of County Road 393, 26 m (85 ft)
east of the SE corner of the house,18 m (58 ft) north of the approximate high
water line of the Bayou, and 0.06 m (0.2 ft) above ground level.
BENCH MARK STAMPING: 9376 C 1992
DESIGNATION: 872 9376 C
MONUMENTATION: Tidal Station disk VM#: 16528
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete racquet ball court OPUS PID#: DQ5789
LATITUDE: 30° 23.9' N ( 30.39814) LONGITUDE: 86° 13.8' W ( -86.22992)
The bench mark is a disk located 79.2 m (260.0 ft) SW of (NOS mark 9367 A 1977,
7.3 m (24.0 ft) SW of a carsonite witness post, and 0.5 m (1.5 ft) SE of a
cement block wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8729376 PUBLICATION DATE: 07/16/2024
Name: SANTA ROSA HOGTOWN BAYOU
NOAA Chart: 11385 Latitude: 30° 24.0' N ( 30.40000)
USGS Quad: FREEPORT Longitude: 86° 13.7' W ( -86.22830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9376 D 1992
DESIGNATION: 872 9376 D
MONUMENTATION: Bench Mark disk VM#: 16529
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Picnic Slab OPUS PID#: DQ5787
LATITUDE: 30° 23.9' N ( 30.39839) LONGITUDE: 86° 13.7' W ( -86.22878)
The bench mark is a disk located 43.5 m (142.6 ft) ESE of NOS bench mark 9367 A
1977, 28.7 m (94.2 ft) west of the approximate centerline of County Road 393,
10.4 m (34.0 ft) NE of the approximate centerline of the landing entrance drive
(Hogtown Bayou Lane), and 2.4 m (8.0 ft) SW of a carsonite witness post.
BENCH MARK STAMPING: 9376 H 2016
DESIGNATION: 872 9736 H
MONUMENTATION: Flange-encased Rod VM#: 24357
AGENCY: National Geodetic Survey (NGS) IDB PID#:
SETTING CLASSIFICATION: Stainless Steel Rod OPUS PID#: DQ5790
LATITUDE: 30° 23.9' N ( 30.39783) LONGITUDE: 86° 13.8' W ( -86.22994)
The bench mark is a flange encased rod located 34.5 m (113.2 ft) east of a
carsonite witness post, 21.9 m (71.8 ft) south of the SW corner of a racquetball
court, 14.0 m (45.8 ft) NNE of concrete light pole number 114504, 6.8 m (22.3
ft) north of the approximate centerline of Hogtown Bayou Lane, and 3.9 m (12.8
ft) NW of the SE end of a concrete sidewalk. The datum point is the top of a
stainless steel rod driven 14.2 m (46.6 ft) to refusal, and encased in 12 cm
(0.4 ft) PVC with a NOS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8729376 PUBLICATION DATE: 07/16/2024
Name: SANTA ROSA HOGTOWN BAYOU
NOAA Chart: 11385 Latitude: 30° 24.0' N ( 30.40000)
USGS Quad: FREEPORT Longitude: 86° 13.7' W ( -86.22830)
T I D A L D A T U M S
Tidal datums at SANTA ROSA HOGTOWN BAYOU based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: April 2021 - July 2021
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8729840 PENSACOLA, PENSACOLA BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.183
MEAN HIGH WATER MHW = 0.177
MEAN SEA LEVEL MSL = 0.090
MEAN TIDE LEVEL MTL = 0.088
North American Vertical Datum NAVD88 = 0.009
MEAN LOWER LOW WATER MLLW = 0.000
MEAN LOW WATER MLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
9376 G 2016 0.641 0.464
9376 A 1977 1.758 1.581
1 1939 0.756 0.579
3 1939 0.841 0.664
9376 C 1992 0.809 0.632
9376 D 1992 0.984 0.807
9376 H 2016 1.003 0.826
Foot Notes:
Benchmarks 1 1939 and 3 1939 are based on one differential leveling connection
and do not meet the quality control standards of the NOS. Therefore, caution
should be used when deriving elevations from these marks.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8729376 PUBLICATION DATE: 07/16/2024
Name: SANTA ROSA HOGTOWN BAYOU
NOAA Chart: 11385 Latitude: 30° 24.0' N ( 30.40000)
USGS Quad: FREEPORT Longitude: 86° 13.7' W ( -86.22830)
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.