U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8729824 PUBLICATION DATE: 04/29/2004
Name: FLORIDATOWN, ESCAMBIA BAY
FL
NOAA Chart: 11382 Latitude: 30° 34.9' N ( 30.58170)
USGS Quad: PACE Longitude: 87° 10.8' W ( -87.18000)
To reach the tidal bench marks from the south end of the U.S. Highway 90 bridge
over Escambia Bay, proceed north on U.S. Highway 90 for 4.0 km (2.5 mi) to a
dirt road leading south to the George Bell residence (9720 North Davis Highway).
The bench marks are along U.S. Route 90 at the north end of Escambia Bay. The
tide gage and staff were located at the dock beside U.S. Highway 90.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 9824 A 1977
DESIGNATION: 872 9824 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 10263
AGENCY: National Ocean Survey (NOS) IDB PID#: BG3609
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 30° 35.0' N ( 30.58330) LONGITUDE: 87° 10.7' W ( -87.17830)
The primary bench mark is a disk set in the median of U.S. Highway 90, 94.79 m
(311.0 ft) NE of the NE end of the northernmost of five bridges over Escambia
Bay, 10.45 m (34.3 ft) SE of the centerline of the westbound lane, and 9.42 m
(30.9 ft) NW of the centerline of the eastbound lane, 12.19 m (40.0 ft) NE of
the centerline of a median crossover, and 0.3 m (1 ft) south of a witness post.
The bench mark is crimped to the top of a galvanized steel rod driven 12.2 m
(40.0 ft), and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8729824 PUBLICATION DATE: 04/29/2004
Name: FLORIDATOWN, ESCAMBIA BAY
FL
NOAA Chart: 11382 Latitude: 30° 34.9' N ( 30.58170)
USGS Quad: PACE Longitude: 87° 10.8' W ( -87.18000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9824 B 1977
DESIGNATION: 872 9824 B TIDAL FLDT
MONUMENTATION: Survey disk VM#: 10264
AGENCY: Florida Department of Transportation
(FLDT) IDB PID#: BG3608
SETTING CLASSIFICATION: Concrete curb of bridge OPUS PID#: BG3608
LATITUDE: 30° 34.9' N ( 30.58170) LONGITUDE: 87° 10.8' W ( -87.18000)
The bench mark is a disk set in top of the curb at the north corner of the
westbound bridge, NW of and across the westbound lane from bench mark 9824 C
1977, 5.15 m (16.9 ft) NW of the centerline of the westbound lane, 0.27 m (0.9
ft) SW of the NE end of the bridge, and 12 cm (0.4 ft) above the level of the
road.
BENCH MARK STAMPING: 9824 C 1977
DESIGNATION: 872 9824 C TIDAL FLDT
MONUMENTATION: Survey disk VM#: 10265
AGENCY: Florida Department of Transportation
(FLDT) IDB PID#: BG3607
SETTING CLASSIFICATION: Concrete guardrail OPUS PID:
LATITUDE: 30° 34.9' N ( 30.58170) LONGITUDE: 87° 10.8' W ( -87.18000)
The bench mark is a disk set in the top of the concrete guardrail at the north
corner of the eastbound bridge, 5.55 m (18.2 ft) NW of the centerline of the
eastbound lane, and 0.9 m (3.0 ft) above the level of the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8729824 PUBLICATION DATE: 04/29/2004
Name: FLORIDATOWN, ESCAMBIA BAY
FL
NOAA Chart: 11382 Latitude: 30° 34.9' N ( 30.58170)
USGS Quad: PACE Longitude: 87° 10.8' W ( -87.18000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9824 D 1977
DESIGNATION: 872 9824 D TIDAL FLDT
MONUMENTATION: Survey disk VM#: 10266
AGENCY: Florida Department of Transportation
(FLDT) IDB PID#: BG3606
SETTING CLASSIFICATION: Concrete guardrail OPUS PID:
LATITUDE: 30° 34.9' N ( 30.58170) LONGITUDE: 87° 10.8' W ( -87.18000)
The bench mark is a disk set in the top of a concrete guardrail at the south
corner of the eastbound bridge, 5.76 m (18.9 ft) SE of the centerline of the
eastbound lane, and 0.15 m (0.5 ft) NE of the SW end of the bridge.
BENCH MARK STAMPING: 9824 E 1977
DESIGNATION: 872 9824 E TIDAL FLDT
MONUMENTATION: Survey disk VM#: 10267
AGENCY: Florida Department of Transportation
(FLDT) IDB PID#: BG3605
SETTING CLASSIFICATION: Concrete curb of bridge OPUS PID:
LATITUDE: 30° 34.9' N ( 30.58170) LONGITUDE: 87° 10.8' W ( -87.18000)
The bench mark is a disk set in the top of the bridge curb at the south corner
of the westbound bridge, NW of and across the eastbound lane from bench mark
9824 D 1977, 5.24 m (17.2 ft) SE of the centerline of the west-bound lane, and
0.09 m (0.3 ft) above the level of the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8729824 PUBLICATION DATE: 04/29/2004
Name: FLORIDATOWN, ESCAMBIA BAY
FL
NOAA Chart: 11382 Latitude: 30° 34.9' N ( 30.58170)
USGS Quad: PACE Longitude: 87° 10.8' W ( -87.18000)
T I D A L D A T U M S
Tidal datums at FLORIDATOWN, ESCAMBIA BAY based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: June 1977 - July 1977
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 = 0.442
MEAN HIGH WATER MHW = 0.423
MEAN TIDE LEVEL MTL = 0.227
MEAN SEA LEVEL MSL = 0.217
North American Vertical Datum NAVD88 = 0.116
MEAN LOW WATER MLW = 0.030
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
9824 A 1977 3.785 3.362
9824 B 1977 4.299 3.876
9824 C 1977 4.847 4.424
9824 D 1977 4.856 4.433
9824 E 1977 4.463 4.040
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8729824 PUBLICATION DATE: 04/29/2004
Name: FLORIDATOWN, ESCAMBIA BAY
FL
NOAA Chart: 11382 Latitude: 30° 34.9' N ( 30.58170)
USGS Quad: PACE Longitude: 87° 10.8' W ( -87.18000)
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.