U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8728626 PUBLICATION DATE: 02/05/2004
Name: ST. GEORGE ISLAND, BAYSIDE
FL
NOAA Chart: 11401 Latitude: 29° 39.2' N ( 29.65330)
USGS Quad: APALACHICOLA Longitude: 84° 53.8' W ( -84.89670)
To reach the tidal bench marks from the junction of Pine Avenue and Franklin
Boulevard on St. George Island, proceed SW on Pine Avenue for 3.2 km (2.0 mi) to
West Sawyer Street, then turn right and proceed north on West Sawyer Street for
0.3 km (0.2 mi). The bench marks are along West Sawyer Street. The tide gage
and staff were located in a dredged canal on a pier reached by a sand spit.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 2 1973
DESIGNATION: 872 8626 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 9854
AGENCY: National Ocean Survey (NOS) IDB PID#: AS0426
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 39.2' N ( 29.65330) LONGITUDE: 84° 53.8' W ( -84.89667)
The primary bench mark is a disk set flush in the top of a concrete monument, 20
m (65 ft) NE of the NE corner of a framed-in trailer, 8 m (25 ft) west of the
centerline of West Sawyer Street, 0.82 m (2.7 ft) east of a concrete property
corner post, 1 m (2 ft) west of power pole #56X-3457R, and 0.55 m (1.8 ft)
north of a concrete witness post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8728626 PUBLICATION DATE: 02/05/2004
Name: ST. GEORGE ISLAND, BAYSIDE
FL
NOAA Chart: 11401 Latitude: 29° 39.2' N ( 29.65330)
USGS Quad: APALACHICOLA Longitude: 84° 53.8' W ( -84.89670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 1 1973
DESIGNATION: 872 8626 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 9853
AGENCY: National Ocean Survey (NOS) IDB PID#: AS0425
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 39.2' N ( 29.65330) LONGITUDE: 84° 53.7' W ( -84.89500)
The bench mark is a disk set flush in the top of a concrete monument, 26 m (86
ft) west of the centerline of West Sawyer Street, 8 m (25 ft) SSW of the SE
corner of a framed-in house trailer, 0.76 m (2.5 ft) north of a concrete witness
post, and 0.46 m (1.5 ft) below street level.
BENCH MARK STAMPING: NO 3 1973
DESIGNATION: 872 8626 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 9855
AGENCY: National Ocean Survey (NOS) IDB PID#: AS0424
SETTING CLASSIFICATION: Concrete monument OPUS PID#: AS0424
LATITUDE: 29° 39.1' N ( 29.65167) LONGITUDE: 84° 53.7' W ( -84.89500)
The bench mark is a disk set flush in the top of a concrete monument, 13 m (44
ft) ESE of the SE corner of a concrete block house, 7 m (24 ft) west of the
centerline of West Sawyer Street, 0.76 m (2.5 ft) east of power pole #56X-3456R,
0.76 m (2.5 ft) east of a concrete property corner marker, 0.76 m (2.5 ft) north
of a concrete witness post, and 0.15 m (0.5 ft) above street level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8728626 PUBLICATION DATE: 02/05/2004
Name: ST. GEORGE ISLAND, BAYSIDE
FL
NOAA Chart: 11401 Latitude: 29° 39.2' N ( 29.65330)
USGS Quad: APALACHICOLA Longitude: 84° 53.8' W ( -84.89670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 4 1973
DESIGNATION: 872 8626 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 9856
AGENCY: National Ocean Survey (NOS) IDB PID#: AS0423
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 39.1' N ( 29.65170) LONGITUDE: 84° 53.7' W ( -84.89500)
The bench mark is a plain brass disk set flush in the top of a concrete
monument, 9 m (29 ft) west of the centerline of West Sawyer Street, 1 m (2 ft)
north of a concrete witness post, 0.61 m (2.0 ft) west of power pole #56X-3455R,
and 0.30 m (1.0 ft) below street level.
BENCH MARK STAMPING: NO 5 1973
DESIGNATION: 872 8626 TIDAL 5
MONUMENTATION: Tidal Station disk VM#: 9857
AGENCY: National Ocean Survey (NOS) IDB PID#: AS0422
SETTING CLASSIFICATION: Concrete monument OPUS PID#: AS0422
LATITUDE: 29° 39.0' N ( 29.65000) LONGITUDE: 84° 53.7' W ( -84.89500)
The bench mark is a disk set flush in the top of a concrete monument, 7.47 m
(24.5 ft) north of the centerline of Pine Avenue, 6.77 m (22.2 ft) west of the
centerline of West Sawyer Street, 0.76 m (2.5 ft) NW of power pole #56X-3238R,
0.40 m (1.3 ft) east of a concrete witness post, and 0.15 m (0.5 ft) above
street level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8728626 PUBLICATION DATE: 02/05/2004
Name: ST. GEORGE ISLAND, BAYSIDE
FL
NOAA Chart: 11401 Latitude: 29° 39.2' N ( 29.65330)
USGS Quad: APALACHICOLA Longitude: 84° 53.8' W ( -84.89670)
T I D A L D A T U M S
Tidal datums at ST. GEORGE ISLAND, BAYSIDE based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: February 1973 - March 1973
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8728690 APALACHICOLA, APALACHICOLA RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.662
MEAN HIGH WATER MHW = 0.606
MEAN SEA LEVEL MSL = 0.381
MEAN TIDE LEVEL MTL = 0.380
MEAN LOW WATER MLW = 0.154
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 2 1973 1.637 1.031
NO 1 1973 1.278 0.672
NO 3 1973 1.817 1.211
NO 4 1973 1.463 0.857
NO 5 1973 2.081 1.475
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8728626 PUBLICATION DATE: 02/05/2004
Name: ST. GEORGE ISLAND, BAYSIDE
FL
NOAA Chart: 11401 Latitude: 29° 39.2' N ( 29.65330)
USGS Quad: APALACHICOLA Longitude: 84° 53.8' W ( -84.89670)
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.