U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8723583 PUBLICATION DATE: 01/23/2004
Name: CARYSFORT REEF LIGHTHOUSE
FL
NOAA Chart: 11462 Latitude: 25° 13.3' N ( 25.22170)
USGS Quad: CARD SOUND Longitude: 80° 12.7' W ( -80.21170)
To reach the tidal bench marks from Worlds Beyond Marina on Key Largo, proceed
by boat east for 10.8 km (6.7 statute mi) to Carysfort Reef Lighthouse. The
bench marks are located on the collar connecting the horizontal braces of the
structure. The tide gage and staff were located on the wooden boat dock.
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: 8723583 PUBLICATION DATE: 01/23/2004
Name: CARYSFORT REEF LIGHTHOUSE
FL
NOAA Chart: 11462 Latitude: 25° 13.3' N ( 25.22170)
USGS Quad: CARD SOUND Longitude: 80° 12.7' W ( -80.21170)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING:
DESIGNATION: 872 3583 BOLT 1
ALIAS: NO STAMPING 1
MONUMENTATION: Bolt VM#: 5926
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Chiseled cross in bolt OPUS PID:
LATITUDE: 25° 13.3' N ( 25.22170) LONGITUDE: 80° 12.7' W ( -80.21170)
The bench mark is a chiseled cross in the westernmost bolt head at the top of a
collar connecting the horizontal brace with the first leg west of the boat dock,
11 m (35 ft) NW of bench mark NO STAMPING 2.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8723583 PUBLICATION DATE: 01/23/2004
Name: CARYSFORT REEF LIGHTHOUSE
FL
NOAA Chart: 11462 Latitude: 25° 13.3' N ( 25.22170)
USGS Quad: CARD SOUND Longitude: 80° 12.7' W ( -80.21170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 872 3583 BOLT 2
ALIAS: NO STAMPING 2
MONUMENTATION: Bolt VM#: 5927
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Chiseled cross in bolt OPUS PID:
LATITUDE: 25° 13.3' N ( 25.22170) LONGITUDE: 80° 12.7' W ( -80.21170)
The bench mark is a chiseled cross in the southernmost bolt head at the top of a
collar connecting a horizontal brace with the second leg SE of the boat dock,
7.38 m (24.2 ft) from the center of the light.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8723583 PUBLICATION DATE: 01/23/2004
Name: CARYSFORT REEF LIGHTHOUSE
FL
NOAA Chart: 11462 Latitude: 25° 13.3' N ( 25.22170)
USGS Quad: CARD SOUND Longitude: 80° 12.7' W ( -80.21170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 872 3583 BOLT 3
ALIAS: NO STAMPING 3
MONUMENTATION: Bolt VM#: 7487
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Chiseled cross in bolt OPUS PID:
LATITUDE: 25° 13.3' N ( 25.22170) LONGITUDE: 80° 12.7' W ( -80.21170)
The bench mark is a chiseled cross in the southwesternmost bolt head at the top
of a collar connecting a horizontal brace with the third leg SE of the boat
dock, 6 m (19 ft) SW of bench mark NO STAMPING 1.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8723583 PUBLICATION DATE: 01/23/2004
Name: CARYSFORT REEF LIGHTHOUSE
FL
NOAA Chart: 11462 Latitude: 25° 13.3' N ( 25.22170)
USGS Quad: CARD SOUND Longitude: 80° 12.7' W ( -80.21170)
T I D A L D A T U M S
Tidal datums at CARYSFORT REEF LIGHTHOUSE based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: July 1975 - July 1975
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8723170 MIAMI BEACH (CITY PIER)
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.776
MEAN HIGH WATER MHW = 0.754
MEAN TIDE LEVEL MTL = 0.405
MEAN SEA LEVEL MSL = 0.404
MEAN LOW WATER MLW = 0.056
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
872 3583 BOLT 1 3.200 2.446
872 3583 BOLT 2 3.201 2.447
872 3583 BOLT 3 3.205 2.451
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8723583 PUBLICATION DATE: 01/23/2004
Name: CARYSFORT REEF LIGHTHOUSE
FL
NOAA Chart: 11462 Latitude: 25° 13.3' N ( 25.22170)
USGS Quad: CARD SOUND Longitude: 80° 12.7' W ( -80.21170)
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.