U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8728942 PUBLICATION DATE: 02/05/2004
Name: CAPE SAN BLAS
FL
NOAA Chart: 11389 Latitude: 29° 40.1' N ( 29.66830)
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.6' W ( -85.36000)
To reach the tidal bench marks from the Post Office in Port St. Joe, proceed 3.9
km (2.4 mi) south along U.S. Highway 98 to State Route 30, then veer right and
proceed south on State Route 30 for 11.0 km (6.9 mi) to Cape San Blas Road
(County Road C-30E), then turn right and proceed west on Cape San Blas Road for
4.5 km (2.8 mi) to a paved road leading to the U.S. Air Force and Coast Guard
installation at Cape San Blas, then proceed west on the paved road for 1.0 km
(0.6 mi) to the installation. The bench marks are at the installation and along
the road. The tide gage and staff were located on a pier at the shore.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 8942 A 1977
DESIGNATION: 872 8942 A
MONUMENTATION: Tidal Station disk VM#: 9905
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 40.1' N ( 29.66830) LONGITUDE: 85° 21.6' W ( -85.36000)
The primary bench mark is a disk located 66 m (216 ft) south from the SE corner
of a sewage treatment plant, 47.49 m (155.8 ft) SE from the SE corner of the
fence for the Loran Antenna, and 26 m (86 ft) east from the SE anchor of the
Loran Antenna. The bench mark is set 6 cm (0.2 ft) below ground level, crimped
to the top of a stainless steel rod driven 11.37 m (37.3 ft) to refusal, and
encased in PVC pipe and concrete kickblock. NOTE: The bench mark was destroyed,
4/21/1989.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8728942 PUBLICATION DATE: 02/05/2004
Name: CAPE SAN BLAS
FL
NOAA Chart: 11389 Latitude: 29° 40.1' N ( 29.66830)
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.6' W ( -85.36000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8942 C 1977
DESIGNATION: 872 8942 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 9907
AGENCY: National Ocean Survey (NOS) IDB PID#: AS0925
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 40.2' N ( 29.67000) LONGITUDE: 85° 21.4' W ( -85.35670)
The bench mark is a disk located 153 m (503 ft) NE of the Coast Guard Loran
Station Light Tower, 55.78 m (183.0 ft) NW of the Coast Guard Flagpole, 27.13 m
(89.0 ft) north of the NW corner of a 4 m x 4 m (12 ft x 12 ft) building, and
0.46 m (1.5 ft) SE of a witness post. The bench mark is set 6 cm (0.2 ft) below
ground level, crimped to the top of a stainless steel rod driven 11.4 m (37.3
ft) to refusal, and encased in a PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 8942 D 1977
DESIGNATION: 872 8942 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 9908
AGENCY: National Ocean Survey (NOS) IDB PID#: AS0924
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 40.2' N ( 29.67000) LONGITUDE: 85° 21.4' W ( -85.35670)
The bench mark is a disk located 48.04 m (157.6 ft) east from the Coast Guard
Flagpole, 25.02 m (82.1 ft) SW from the inside corner of the wye formed by the
entrance road to the U.S.A.F./Coast Guard installation and an access road
leading to the beach, 11.25 m (36.9 ft) west of guy pole marked #5-10583, and
0.3 m (1 ft) west of a witness post. The bench mark is set 12 cm (0.4 ft) below
ground level, crimped to the top of a stainless steel rod driven 14.6 m (48 ft)
to refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8728942 PUBLICATION DATE: 02/05/2004
Name: CAPE SAN BLAS
FL
NOAA Chart: 11389 Latitude: 29° 40.1' N ( 29.66830)
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.6' W ( -85.36000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: A 339 1977
DESIGNATION: A 339
MONUMENTATION: Bench Mark disk VM#: 9909
AGENCY: National Geodetic Survey (NGS) IDB PID#: AS0380
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 29° 40.2' N ( 29.67000) LONGITUDE: 85° 21.6' W ( -85.36000)
The primary bench mark is a disk located 105 m (345 ft) SW of the centerline of
the road, 94 m (307 ft) west of the west corner of an elevated coast guard
building, 77 m (251 ft) NW of the north corner of a wooden fence surrounding a
Loran Antenna Tower, 4 m (12 ft) south of the southwesternmost of 3 palm trees,
3 m (11 ft) north of a palm tree, and 0.30 m (1.0 ft) SE of a witness post. The
bench mark is set 30 cm (1 ft) above ground level, crimped to the top of a
copper-clad steel rod driven 21.9 m (72 ft) to refusal, and encased in PVC pipe
and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8728942 PUBLICATION DATE: 02/05/2004
Name: CAPE SAN BLAS
FL
NOAA Chart: 11389 Latitude: 29° 40.1' N ( 29.66830)
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.6' W ( -85.36000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: B 339 1977
DESIGNATION: B 339
MONUMENTATION: Bench Mark disk VM#: 16524
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AS0379
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 29° 40.4' N ( 29.67330) LONGITUDE: 85° 21.1' W ( -85.35170)
The bench mark is a disk located near the junction of the paved road and Cape
San Blas Road (County Road C-30E), 18.0 m (59.0 ft) south of the centerline of
Cape San Blas Road, 11.28 m (37.0 ft) NW of the centerline of the road to the
Coast Guard installation, 2.74 m (9.0 ft) NW of a powerline pole, and 0.3 m (1
ft) SE of a witness post. The bench mark is set 1 m (3 ft) below the level of
the road, crimped to the top of a copper-clad steel rod driven 21.0 m (69 ft) to
refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8728942 PUBLICATION DATE: 02/05/2004
Name: CAPE SAN BLAS
FL
NOAA Chart: 11389 Latitude: 29° 40.1' N ( 29.66830)
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.6' W ( -85.36000)
T I D A L D A T U M S
Tidal datums at CAPE SAN BLAS based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: October 1977 - January 1978
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 = 0.438
MEAN HIGH WATER MHW = 0.422
North American Vertical Datum NAVD88 = 0.233
MEAN SEA LEVEL MSL = 0.227
MEAN TIDE LEVEL MTL = 0.226
MEAN LOW WATER MLW = 0.029
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
8942 A 1977 1.471 1.049
8942 C 1977 1.617 1.195
8942 D 1977 1.869 1.447
A 339 1977 1.768 1.346
B 339 1977 2.184 1.762
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8728942 PUBLICATION DATE: 02/05/2004
Name: CAPE SAN BLAS
FL
NOAA Chart: 11389 Latitude: 29° 40.1' N ( 29.66830)
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.6' W ( -85.36000)
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.