U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8723795 PUBLICATION DATE: 01/23/2004
Name: WHALE HARBOR MARINA
FL
NOAA Chart: 11463 Latitude: 24° 56.4' N ( 24.94000)
USGS Quad: PLANTATION KEY Longitude: 80° 36.5' W ( -80.60830)
To reach the tidal bench marks from the post office in Islamorada, proceed 2.1
km (1.3 mi) NE on U.S. Highway 1 to Holiday Isle Resort on the right. The bench
marks are located in the vicinity of Holiday Isle Resort and along the highway.
The tide gage and staff were located on the sea wall at the marina.
T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8723795 PUBLICATION DATE: 01/23/2004
Name: WHALE HARBOR MARINA
FL
NOAA Chart: 11463 Latitude: 24° 56.4' N ( 24.94000)
USGS Quad: PLANTATION KEY Longitude: 80° 36.5' W ( -80.60830)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: M 276 1966
DESIGNATION: M 276
MONUMENTATION: Bench Mark disk VM#: 6223
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AA0428
SETTING CLASSIFICATION: Concrete manhole base OPUS PID:
LATITUDE: 24° 56.6' N ( 24.94330) LONGITUDE: 80° 36.4' W ( -80.60670)
The primary bench mark is a disk set in the top of the south corner of a 3 m (10
ft) square concrete manhole base across Highway 1 from the Holiday Isle Motel
office, 9.91 m (32.5 ft) NW of the centerline of U.S. Highway 1, 0.3 (1 ft)
north of a metal witness post, and 0.3 m (1 ft) below highway level.
BENCH MARK STAMPING: NO 1 1971
DESIGNATION: 872 3795 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 6224
AGENCY: National Ocean Survey (NOS) IDB PID#: AA0802
SETTING CLASSIFICATION: Concrete manhole base OPUS PID:
LATITUDE: 24° 56.4' N ( 24.94000) LONGITUDE: 80° 36.6' W ( -80.61000)
The bench mark is a disk set in the top of a concrete base for a manhole near
the NE end of the Whale Harbor Channel Bridge, 15.82 m (51.9 ft) NE of the NE
bridge rail, 9.33 m (30.6 ft) SE of the centerline of U.S. Highway 1, 5 m (15
ft) NE of the edge of the water near the NE end of the bridge over Whale Harbor
Channel, and 2 m (8 ft) below highway level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8723795 PUBLICATION DATE: 01/23/2004
Name: WHALE HARBOR MARINA
FL
NOAA Chart: 11463 Latitude: 24° 56.4' N ( 24.94000)
USGS Quad: PLANTATION KEY Longitude: 80° 36.5' W ( -80.60830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 2 1971
DESIGNATION: 872 3795 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 6225
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AA0801
SETTING CLASSIFICATION: Concrete manhole base OPUS PID:
LATITUDE: 24° 56.5' N ( 24.94170) LONGITUDE: 80° 36.5' W ( -80.60830)
The bench mark is a disk set in top of a concrete base for a manhole, 80 m (264
ft) NE of the bridge over Whale Harbor Channel, 12 m (41 ft) SE of the
centerline of U.S. Highway 1, and 3.84 m (12.6 ft) NW of the edge of the water,
and 0.3 m (1 ft) below highway level.
BENCH MARK STAMPING: NO 3 1971
DESIGNATION: 872 3795 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 6226
AGENCY: National Ocean Survey (NOS) IDB PID#: AA0800
SETTING CLASSIFICATION: Concrete base OPUS PID:
LATITUDE: 24° 56.5' N ( 24.94170) LONGITUDE: 80° 36.5' W ( -80.60830)
The bench mark is a disk set in the SE corner of the concrete base of a Standard
Oil sign, 55.08 m (180.7 ft) SE of the centerline of the U.S. Highway 1, 9.02 m
(29.6 ft) NW of the channel sea wall leading to the Holiday Isle Resort Marina,
and 0.3 m (1 ft) below highway level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8723795 PUBLICATION DATE: 01/23/2004
Name: WHALE HARBOR MARINA
FL
NOAA Chart: 11463 Latitude: 24° 56.4' N ( 24.94000)
USGS Quad: PLANTATION KEY Longitude: 80° 36.5' W ( -80.60830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 4 1971
DESIGNATION: 872 3795 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 6227
AGENCY: National Ocean Survey (NOS) IDB PID#: AA0799
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 24° 56.5' N ( 24.94170) LONGITUDE: 80° 36.5' W ( -80.60830)
The bench mark is a disk set in the top of the north corner of the sea wall of
Holiday Isle Resort Marina, 40 m (131 ft) SE of the centerline of U.S. Highway
1, and 1 m (2 ft) below highway level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8723795 PUBLICATION DATE: 01/23/2004
Name: WHALE HARBOR MARINA
FL
NOAA Chart: 11463 Latitude: 24° 56.4' N ( 24.94000)
USGS Quad: PLANTATION KEY Longitude: 80° 36.5' W ( -80.60830)
T I D A L D A T U M S
Tidal datums at WHALE HARBOR MARINA based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: May 1975 - May 1975
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8724580 KEY WEST
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.514
MEAN HIGH WATER MHW = 0.480
North American Vertical Datum NAVD88 = 0.463
MEAN TIDE LEVEL MTL = 0.246
MEAN SEA LEVEL MSL = 0.229
MEAN LOW WATER MLW = 0.012
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
M 276 1966 1.068 0.588
NO 1 1971 2.563 2.083
NO 2 1971 1.261 0.781
NO 3 1971 1.724 1.244
NO 4 1971 1.358 0.878
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8723795 PUBLICATION DATE: 01/23/2004
Name: WHALE HARBOR MARINA
FL
NOAA Chart: 11463 Latitude: 24° 56.4' N ( 24.94000)
USGS Quad: PLANTATION KEY Longitude: 80° 36.5' W ( -80.60830)
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.