U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8723453 PUBLICATION DATE: 06/12/2009
Name: ADAMS KEY
FL
NOAA Chart: 11463 Latitude: 25° 23.8' N ( 25.39670)
USGS Quad: ELLIOTT KEY Longitude: 80° 14.0' W ( -80.23330)
To reach the tidal bench marks from Elliott Key Harbor, proceed by boat in
Biscayne Bay for 7.1 km (3.8 nm) to the south side of Adams Key. The bench
marks are located on the south side of Adams Key. The tide station was located
on the east side of a "T" pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 8 1974
DESIGNATION: 872 3453 TIDAL 8
MONUMENTATION: Tidal Station disk VM#: 5857
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 25° 23.8' N ( 25.39670) LONGITUDE: 80° 14.0' W ( -80.23330)
The primary bench mark is a disk set flush in a concrete monument near the south
end of Adams Key, 31.46 m (103.2 ft) ENE of bench mark 3453 H 1987, 21.12 m
(69.3 ft) SSW of the SW corner of Building #105, 16.46 m (54.0 ft) SSE of the SE
corner of building #103, and 2.29 m (7.5 ft) ENE of a palm tree.
BENCH MARK STAMPING: 3453 F 1987
DESIGNATION: 872 3453 F TIDAL
MONUMENTATION: Tidal Station disk VM#: 5860
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete pier decking OPUS PID:
LATITUDE: 25° 23.8' N ( 25.39670) LONGITUDE: 80° 14.0' W ( -80.23330)
The bench mark is a disk set in the concrete pier decking at the Adams Key
Information Station, 9.48 m (31.1 ft) south of the NW corner of the pier, and
0.18 m (0.6 ft) east of the west side of the pier.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8723453 PUBLICATION DATE: 06/12/2009
Name: ADAMS KEY
FL
NOAA Chart: 11463 Latitude: 25° 23.8' N ( 25.39670)
USGS Quad: ELLIOTT KEY Longitude: 80° 14.0' W ( -80.23330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3453 G 1987
DESIGNATION: 872 3453 G TIDAL
MONUMENTATION: Tidal Station disk VM#: 5861
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete base OPUS PID:
LATITUDE: 25° 23.8' N ( 25.39670) LONGITUDE: 80° 14.0' W ( -80.23330)
The bench mark is a disk set in the 1 m x 1 m (4 ft x 4 ft) square concrete base
for a flagpole, 35.91 m (117.8 ft) WNW of the NW corner of the pier, 7.86 m
(25.8 ft) SSE of the center of the front steps to the museum, and 0.18 m (0.6
ft) SSE of the flagpole.
BENCH MARK STAMPING: 3453 H 1987
DESIGNATION: 872 3453 H TIDAL
MONUMENTATION: Tidal Station disk VM#: 5862
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete base OPUS PID:
LATITUDE: 25° 23.8' N ( 25.39670) LONGITUDE: 80° 14.0' W ( -80.23330)
The bench mark is a disk set in a 2.38 m x 1.22 m (7.8 ft x 4.0 ft) concrete
base for a fire station, 45.26 m (148.5 ft) NNW of bench mark 3453 F 1987, 31.12
m (102.1 ft) NNW of the center of the back steps of the museum, and 0.40 m (1.3
ft) ESE of a fire hydrant.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8723453 PUBLICATION DATE: 06/12/2009
Name: ADAMS KEY
FL
NOAA Chart: 11463 Latitude: 25° 23.8' N ( 25.39670)
USGS Quad: ELLIOTT KEY Longitude: 80° 14.0' W ( -80.23330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3453 J 1987
DESIGNATION: 872 3453 J TIDAL
MONUMENTATION: Tidal Station disk VM#: 5863
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete ramp OPUS PID:
LATITUDE: 25° 23.8' N ( 25.39670) LONGITUDE: 80° 14.0' W ( -80.23330)
The bench mark is a disk set flush in a concrete seaplane ramp, 60.81 m (199.5
ft) WSW of bench mark 3453 H 1987, 30.60 m (100.4 ft) west of the SW corner of
the screen porch for the southwestmost house, and 5.58 m (18.3 ft) south of the
NE corner of the ramp.
BENCH MARK STAMPING: 3453 K 1987
DESIGNATION: 872 3453 K TIDAL
MONUMENTATION: Tidal Station disk VM#: 5864
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete base OPUS PID:
LATITUDE: 25° 23.8' N ( 25.39670) LONGITUDE: 80° 14.0' W ( -80.23330)
The bench mark is a disk set in the east corner of the 1 m x 1 m (4 ft x 4 ft)
concrete base for a radio tower, 38.56 m (126.5 ft) north of bench mark 3453 H
1987, 24.48 m (80.3 ft) WNW of the NW corner of Building #103, 11.28 m (37.0 ft)
NNW of wooden pull-up pole # 8, and 4.42 m (14.5 ft) SE of a 1 m (3 ft) high
concrete block retaining wall around a sewer outlet.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8723453 PUBLICATION DATE: 06/12/2009
Name: ADAMS KEY
FL
NOAA Chart: 11463 Latitude: 25° 23.8' N ( 25.39670)
USGS Quad: ELLIOTT KEY Longitude: 80° 14.0' W ( -80.23330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3453 L 1987
DESIGNATION: 872 3453 L TIDAL
MONUMENTATION: Tidal Station disk VM#: 5865
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 25° 23.8' N ( 25.39670) LONGITUDE: 80° 14.0' W ( -80.23330)
The bench mark is a disk located at the approximate mowed grass line, 52.30 m
(171.6 ft) east of the NE corner of Building # 103, and 12.80 m (42.0 ft) NE of
the NE face of a cistern. The bench mark is set at ground level, crimped to the
top of a stainless steel rod driven 0.46 m (1.5 ft) to refusal, and encased in a
PVC pipe projecting 0.1 m (0.3 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8723453 PUBLICATION DATE: 06/12/2009
Name: ADAMS KEY
FL
NOAA Chart: 11463 Latitude: 25° 23.8' N ( 25.39670)
USGS Quad: ELLIOTT KEY Longitude: 80° 14.0' W ( -80.23330)
T I D A L D A T U M S
Tidal datums at ADAMS KEY based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: August 1987 - August 1987
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8723962 KEY COLONY BEACH
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.502
MEAN HIGH WATER MHW = 0.501
MEAN SEA LEVEL MSL = 0.282
MEAN TIDE LEVEL MTL = 0.275
MEAN LOW WATER MLW = 0.049
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 8 1974 1.459 0.958
3453 F 1987 1.359 0.858
3453 G 1987 1.168 0.667
3453 H 1987 1.558 1.057
3453 J 1987 0.711 0.210
3453 K 1987 1.250 0.749
3453 L 1987 1.058 0.557
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8723453 PUBLICATION DATE: 06/12/2009
Name: ADAMS KEY
FL
NOAA Chart: 11463 Latitude: 25° 23.8' N ( 25.39670)
USGS Quad: ELLIOTT KEY Longitude: 80° 14.0' W ( -80.23330)
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.