U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 1 of 5
Station ID: 8728949 PUBLICATION DATE: 03/09/2004
Name: RICHARDSON HAMMOCK, ST. JOSEPH BAY
FLORIDA
NOAA Chart: 11389 Latitude: 29° 41.4' N
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.8' W
To reach the tidal bench marks from the Port St. Joe Post Office, proceed SE on
U.S. Highway 98 for 3.8 km (2.4 mi), to the junction with State Route 30, then
veer right and proceed south on State Route 30 for 11.1 km (6.9 mi) to County
Road C-30E (Cape San Blas Road), then turn right and proceed west and north on
County Road C-30E for 6.7 km (4.2 mi) to a sand road leading NE, then turn right
and proceed NE on the sand road for 0.8 km (0.5 mi) to its end. The bench marks
are along the sand road and County Road C-30E. The tide gage and staff were
located on a platform built 45.72 m (150.0 ft) offshore in St. Joseph Bay, at
the east end of the sand road.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 8949 A 1976
DESIGNATION: 872 8949 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 9915
AGENCY: National Ocean Survey (NOS) PID#: AS0930
SETTING CLASSIFICATION: Copper-clad steel rod
The primary bench mark is a disk located at the top of the bluff, 11.58 m (38.0
ft) SW of the shoreline, 9.05 m (29.7 ft) south of a palm tree with a "No
Trespassing" sign, 4.27 m (14.0 ft) SSE of the centerline of a dirt path leading
to the beach from the end of the sand road, 1.52 m (5.0 ft) west of the edge of
the bluff, 0.76 m (2.5 ft) NW of an oak tree, and 0.3 m (1 ft) SSE of a witness
post. The bench mark is set 0.18 m (0.6 ft) below ground level, crimped to the
top of a copper-clad steel rod driven 12.2 m (40 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 2 of 5
Station ID: 8728949 PUBLICATION DATE: 03/09/2004
Name: RICHARDSON HAMMOCK, ST. JOSEPH BAY
FLORIDA
NOAA Chart: 11389 Latitude: 29° 41.4' N
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8949 C 1976
DESIGNATION: 872 8949 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 9917
AGENCY: National Ocean Survey (NOS) PID#: AS0928
SETTING CLASSIFICATION: Copper-clad steel rod
The bench mark is a disk located near the junction of the sand road and County
Road C-30E, 134 m (438 ft) SE of bench mark 8949 D 1976, 16.67 m (54.7 ft) ENE
of the centerline of County Road C-30E, 2.68 m (8.8 ft) NW of the centerline of
the sand road, 1.98 m (6.5 ft) NE of the NW gate post at the entrance to the
sand road, and 0.37 m (1.2 ft) SW of a witness post. The bench mark is set 0.09
m (0.3 ft) below ground level, crimped to the top of a copper-clad steel rod
driven 12.2 m (40 ft) to refusal and encased in a PVC pipe and concrete
kickblock.
BENCH MARK STAMPING: 8949 D 1976
DESIGNATION: 872 8949 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 9918
AGENCY: National Ocean Survey (NOS) PID#: AS0932
SETTING CLASSIFICATION: Copper-clad steel rod
The bench mark is a disk located 136 m (447 ft) NW of the NW gate post at the
entrance to the sand road, 134 m (438 ft) NW of bench mark 8949 C 1976, 35.45 m
(116.3 ft) SSW of and across County Road C-30E from powerline pole #57Y2884R,
17.34 m (56.9 ft) SW of the centerline of County Road C-30E, 1.16 m (3.8 ft) ENE
of a pine tree with a witness sign attached, and 0.3 m (1 ft) NE of a witness
post. The bench mark is set 0.21 m (0.7 ft) below ground level, crimped to the
top of a copper-clad steel rod driven 12.2 m (40 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 5
Station ID: 8728949 PUBLICATION DATE: 03/09/2004
Name: RICHARDSON HAMMOCK, ST. JOSEPH BAY
FLORIDA
NOAA Chart: 11389 Latitude: 29° 41.4' N
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BLAS 1935
DESIGNATION: BLAS
MONUMENTATION: Triangulation Station disk VM#: 9919
AGENCY: US Coast and Geodetic Survey (USC&GS) PID#: AS0771
SETTING CLASSIFICATION: Clay tile pipe
The bench mark is a disk located 140 m (460 ft) north of bench mark 8949 A 1976,
35.91 m (117.8 ft) NNW of a cedar tree, 18.29 m (60.0 ft) south of a palmetto
tree and 15.00 m (49.2 ft) NW of a second palmetto tree. All reference trees
are designated by triangular blazes. NOTE: Mark not found in 1994.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8728949 PUBLICATION DATE: 03/09/2004
Name: RICHARDSON HAMMOCK, ST. JOSEPH BAY
FLORIDA
NOAA Chart: 11389 Latitude: 29° 41.4' N
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.8' W
T I D A L D A T U M S
Tidal datums at RICHARDSON HAMMOCK, ST. JOSEPH BAY based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: January 1981 - March 1981
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8728912 PORT ST. JOE
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER (MHHW) = 0.522
MEAN HIGH WATER (MHW) = 0.436
MEAN SEA LEVEL (MSL) = 0.253
MEAN TIDE LEVEL (MTL) = 0.241
NORTH AMERICAN VERTICAL DATUM-1988 (NAVD) = 0.139
MEAN LOW WATER (MLW) = 0.046
MEAN LOWER LOW WATER (MLLW) = 0.000
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
8949 A 1976 2.736 2.300
8949 C 1976 2.585 2.149
8949 D 1976 1.345 0.909
BLAS 1935 0.766 0.330
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8728949 PUBLICATION DATE: 03/09/2004
Name: RICHARDSON HAMMOCK, ST. JOSEPH BAY
FLORIDA
NOAA Chart: 11389 Latitude: 29° 41.4' N
USGS Quad: CAPE SAN BLAS Longitude: 85° 21.8' W
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 (NAVD 88).
NGVD 29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded. NGVD 29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads. NGVD 29 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 NGVD 29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at
National Geodetic Survey.
NAVD 88 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. NAVD 88 replaces NGVD 29 as the national
standard geodetic reference for heights. Bench mark elevations relative to
NAVD 88 are available from NGS through the World Wide Web at
National Geodetic Survey.
NGVD 29 and NAVD 88 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 NAVD 88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD 88 elevations.
The NAVD 88 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, NAVD 88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD 88 elevations listed for
each bench mark in the NGS database.