U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 07/20/1987
Station ID: 8724951 SUPERCEDED DATE: 04/21/2003
Name: PANTHER KEY, GULF OF MEXICO
FLORIDA
NOAA Chart: 11429 Latitude: 25° 51.5' N
USGS Quad: PANTHER KEY Longitude: 81° 32.3' W
To reach the tidal bench marks from Royal Palm Hammock proceed east on U.S.
Highway 41 for 6 miles (10 km) to the Remuda Ranch Marina, then by boat south on
Fakha Union Canal to Fakha Union River, then follow privately-maintained
navigational aids to the vicinity of Daybeacon #8, then south to the SE end of a
large key located directly NE of Panther Key, (total distance by boat is about
6.5 miles (10.5 km)). The bench marks are located near the southern tip of the
key, separated from Panther Key by a narrow creek. The gage and staff were
located 100 feet (30 m) offshore and south of Bench Mark 4951 A 1978.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4951 A 1978
MONUMENTATION: Survey Disk VM#: 9715
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is near a mangrove tree on the southern tip of the key, 21 feet
(6 m) south of a small tidal pond, 20 feet (6 m) NW of the waters edge, 4.6 feet
(1.4 m) NE of a 0.5-foot (0.2 m) diameter mangrove tree, and 0.5 foot (0.2 m)
north of a witness post. The bench mark is 1 foot (0.3 m) above ground level,
crimped to a galvanized steel rod driven 30 feet (9 m) to refusal, and encased
in a PVC pipe.
BENCH MARK STAMPING: 4951 B 1978
MONUMENTATION: Survey Disk VM#: 9716
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is 98.0 feet (29.9 m) north of the mangrove edge, 87.0 feet (26.5
m) north of Bench Mark 4951 A 1978, 21.6 feet (6.6 m) east of a 0.7-foot (0.2 m)
diameter mangrove tree, and 1.0 foot (0.3 m) north of a witness post. The bench
mark is 1.3 feet (0.4 m) above ground level, crimped to a galvanized steel rod
driven 38 feet (12 m) to refusal, and encased in a PVC pipe. (NOTE: Mark will
be submerged at high tide.)
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 07/20/1987
Station ID: 8724951 SUPERCEDED DATE: 04/21/2003
Name: PANTHER KEY, GULF OF MEXICO
FLORIDA
NOAA Chart: 11429 Latitude: 25° 51.5' N
USGS Quad: PANTHER KEY Longitude: 81° 32.3' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4951 C 1978
MONUMENTATION: Survey Disk VM#: 9717
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is 131.0 feet (39.9 m) SW of Bench Mark 4951 B 1978, 87 feet (27
m) west of Bench Mark 4951 A 1978, 42 feet (13 m) SE of a 1.0-foot (0.3 m)
diameter mangrove tree, 27.0 feet (8.2 m) SW of an 0.7-foot (0.2 m) diameter
mangrove tree, 23 feet (7 m) north of the waters edge, 17.6 feet (5.4 m) east of
a 0.8-foot (0.2 m) diameter mangrove tree, and 0.7 foot (0.2 m) south of a
witness post. The bench mark is 1.0 foot (0.3 m) above ground level, crimped to
a galvanized steel rod driven 38 feet (12 m) to refusal, and encased in a PVC
pipe. (NOTE: Mark will be submerged at high tide.)
BENCH MARK STAMPING: 4951 D 1978
MONUMENTATION: Survey Disk VM#: 9718
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is on a shell ridge, 94.0 feet (28.7 m) NW of Bench Mark 4951 C
1978, 28.0 feet (8.5 m) NE of the mangrove edge, 11 feet (3 m) SW of a small
pond, 9.6 feet (2.9 m) SW of a 0.8-foot (0.2 m) diameter white mangrove tree,
and 0.4 foot (0.1 m) east of a witness post. The bench mark is 0.3 foot
(0.1 m) above ground level, crimped to a galvanized steel rod riven 32 feet (10
m) to refusal, and encased in a PVC pipe. (NOTE: Mark will be submerged at
high tide.)
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 07/20/1987
Station ID: 8724951 SUPERCEDED DATE: 04/21/2003
Name: PANTHER KEY, GULF OF MEXICO
FLORIDA
NOAA Chart: 11429 Latitude: 25° 51.5' N
USGS Quad: PANTHER KEY Longitude: 81° 32.3' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4951 E 1978
MONUMENTATION: Survey Disk VM#: 9719
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is 121.0 feet (36.9 m) north of Bench Mark 4951 A 1978, 20.0 feet
(6.1 m) NW of the waters edge, 18.8 feet (5.7 m) north of a mangrove tree
located at the waters edge, 8.0 feet (2.4 m) NE of a 0.7-foot (0.2 m) diameter
mangrove tree, and 5.5 feet (1.7 m) NW of a witness sign on a tree. The bench
mark is 0.4 foot (0.1 m) above ground level, crimped to a galvanized steel rod
driven 30 feet (9 m) to refusal, and encased in a PVC pipe. (NOTE: Mark will
be submerged at high tide.)
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 07/20/1987
Station ID: 8724951 SUPERCEDED DATE: 04/21/2003
Name: PANTHER KEY, GULF OF MEXICO
FLORIDA
NOAA Chart: 11429 Latitude: 25° 51.5' N
USGS Quad: PANTHER KEY Longitude: 81° 32.3' W
T I D A L D A T U M S
Tidal datums at PANTHER KEY, GULF OF MEXICO based on:
LENGTH OF SERIES: 6 MONTHS
TIME PERIOD: DECEMBER 1977-MAY 1978
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8724919 CHOKOLOSKEE
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (05/04/1978) = 5.41
MEAN HIGHER HIGH WATER MHHW = 4.26
MEAN HIGH WATER MHW = 4.01
MEAN TIDE LEVEL MTL = 2.32
MEAN LOW WATER MLW = 0.63
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (01/10/1978) = -1.47
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
4951 A 1978 4.30 0.29
4951 B 1978 3.23 -0.78
4951 C 1978 3.39 -0.62
4951 D 1978 3.67 -0.34
4951 E 1978 3.46 -0.55
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 07/20/1987
Station ID: 8724951 SUPERCEDED DATE: 04/21/2003
Name: PANTHER KEY, GULF OF MEXICO
FLORIDA
NOAA Chart: 11429 Latitude: 25° 51.5' N
USGS Quad: PANTHER KEY Longitude: 81° 32.3' 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 (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 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.