U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8723808 PUBLICATION DATE: 09/15/2004
Name: UPPER MATECUMBE KEY,FLORIDA BAY
FL
NOAA Chart: 11449 Latitude: 24° 55.5' N ( 24.92500)
USGS Quad: UPPER MATECUMBE KEY Longitude: 80° 37.9' W ( -80.63170)
To reach the tidal bench marks from the post office in Islamorada, proceed 0.89
km (0.55 mi) SW on U.S. Highway 1, then 0.08 km (0.05 mi) NW on Last Street for
to a 90 degree left turn. Continue 0.08 km (0.05 mi) SW to a private drive
leading to the Caribbean Sunset Resort, then 0.08 km (0.05 mi) NW on the private
drive its end. The bench marks are located in the vicinity of the Sunset
Resort. The tide gage and staff were located on a bulkhead on Florida Bay at
the resort.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1971
DESIGNATION: 872 3808 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 10806
AGENCY: National Ocean Survey (NOS) IDB PID#: AA0836
SETTING CLASSIFICATION: Concrete pier OPUS PID:
LATITUDE: 24° 55.5' N ( 24.92500) LONGITUDE: 80° 37.9' W ( -80.63170)
The primary bench mark is a disk set flush at the NW end of the concrete pier on
the west side of a boat basin at the Caribbean Sunset Resort, and 2.62 m (8.6
ft) south of the north corner of the pier.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8723808 PUBLICATION DATE: 09/15/2004
Name: UPPER MATECUMBE KEY,FLORIDA BAY
FL
NOAA Chart: 11449 Latitude: 24° 55.5' N ( 24.92500)
USGS Quad: UPPER MATECUMBE KEY Longitude: 80° 37.9' W ( -80.63170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 2 1971
DESIGNATION: 872 3808 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 10807
AGENCY: National Ocean Survey (NOS) IDB PID#: AA0837
SETTING CLASSIFICATION: Concrete pier OPUS PID:
LATITUDE: 24° 55.5' N ( 24.92500) LONGITUDE: 80° 37.9' W ( -80.63170)
The bench mark is a disk set flush near the SE end of the concrete pier on the
SW side of the boat basin at the Caribbean Sunsetw Resort, 29 m (95 ft) SE of
bench mark NO 1 1971, 9 m (30 ft) NW of the NW corner of a boat shed, and 0.21 m
(0.7 ft) SW of the edge of the seawall.
BENCH MARK STAMPING: NO 3 1971
DESIGNATION: 872 3808 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 10808
AGENCY: National Ocean Survey (NOS) IDB PID#: AA0835
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 24° 55.5' N ( 24.92500) LONGITUDE: 80° 37.9' W ( -80.63170)
The bench mark is a disk set flush in the top of a seawall, 7.74 m (25.4 ft)
north of the north wall of the apartment building, 6.25 m (20.5 ft) SW of the SW
side of the boat ramp, and 0.3 m (1.0 ft) east of the corner of the seawall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8723808 PUBLICATION DATE: 09/15/2004
Name: UPPER MATECUMBE KEY,FLORIDA BAY
FL
NOAA Chart: 11449 Latitude: 24° 55.5' N ( 24.92500)
USGS Quad: UPPER MATECUMBE KEY Longitude: 80° 37.9' W ( -80.63170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 4 1971
DESIGNATION: 872 3808 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 10809
AGENCY: National Ocean Survey (NOS) IDB PID#: AA0834
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 24° 55.5' N ( 24.92500) LONGITUDE: 80° 37.9' W ( -80.63170)
The bench mark is a disk set flush in the top of a seawall, 14.08 m (46.2 ft) NE
of the NE corner of the apartment building, and 2.59 m (8.5 ft) east of the east
side of the boat ramp.
BENCH MARK STAMPING: NO 5 1971
DESIGNATION: 872 3808 TIDAL 5
MONUMENTATION: Tidal Station disk VM#: 10810
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 24° 55.5' N ( 24.92500) LONGITUDE: 80° 37.9' W ( -80.63170)
The bench mark is a disk set flush with the surface, located behind Jerry's
Sunset Inn, 18.32 m (60.1 ft) NE of walkway leading to private island, and 0.76
m (2.5 ft) east from east corner of concrete seawall surrounding private island.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8723808 PUBLICATION DATE: 09/15/2004
Name: UPPER MATECUMBE KEY,FLORIDA BAY
FL
NOAA Chart: 11449 Latitude: 24° 55.5' N ( 24.92500)
USGS Quad: UPPER MATECUMBE KEY Longitude: 80° 37.9' W ( -80.63170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3808 G 1982
DESIGNATION: 872 3808 G
MONUMENTATION: Tidal Station disk VM#: 10811
AGENCY: National Ocean Survey (NOS) IDB PID#: AA0832
SETTING CLASSIFICATION: Concrete box drain OPUS PID:
LATITUDE: 24° 55.4' N ( 24.92330) LONGITUDE: 80° 37.8' W ( -80.63000)
The bench mark is a disk set on the SE edge of a 1.4 m x 0.8 m (4.6 ft x 2.6 ft)
concrete box drain in the driveway for the Sunset Inn Restaurant and Bar, near
the intersection of U.S. Highway 1 and Last Street, 43.59 m (143.0 ft) SW of the
centerline of Last Street, 15.15 m (49.7 ft) NW of the centerline of U.S.
Highway 1, 14.63 m (48.0 ft) SW of concrete power pole #655, and 0.15 m (0.5
ft) SE of the SE end of a metal drain cover.
BENCH MARK STAMPING: Q 276 1966
DESIGNATION: 872 3808 TIDAL Q
MONUMENTATION: Tidal Station disk VM#: 10812
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AA0424
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 24° 55.7' N ( 24.92830) LONGITUDE: 80° 37.4' W ( -80.62330)
The bench mark is a disk set in the top of a 2.13 m (7.0 ft) square concrete
foundation for a manhole for water line, about 0.6 km (0.4 mi) SW of the post
office in Islamorada, 91 m (300 ft) south of the south corner of Pouchers Market
on U.S. Highway 1, 14m (45 ft) SE of the centerline of the highway, 6 m (21 ft)
SW of the centerline of a black-top road, and 0.3 m (1.0 ft) above highway
level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8723808 PUBLICATION DATE: 09/15/2004
Name: UPPER MATECUMBE KEY,FLORIDA BAY
FL
NOAA Chart: 11449 Latitude: 24° 55.5' N ( 24.92500)
USGS Quad: UPPER MATECUMBE KEY Longitude: 80° 37.9' W ( -80.63170)
T I D A L D A T U M S
Tidal datums at UPPER MATECUMBE KEY,FLORIDA BAY based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: March 1972 - February 1973
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8724580 KEY WEST
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/07/1972) = 0.436
North American Vertical Datum NAVD88 = 0.315
MEAN HIGHER HIGH WATER MHHW = 0.188
MEAN HIGH WATER MHW = 0.163
MEAN TIDE LEVEL MTL = 0.089
MEAN SEA LEVEL MSL = 0.086
MEAN LOW WATER MLW = 0.015
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (02/05/1972) = -0.204
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 1 1971 1.071 0.908
NO 2 1971 1.174 1.011
NO 3 1971 1.267 1.104
NO 4 1971 1.170 1.007
NO 5 1971 0.961 0.798
3808 G 1982 2.402 2.239
Q 276 1966 2.570 2.407
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8723808 PUBLICATION DATE: 09/15/2004
Name: UPPER MATECUMBE KEY,FLORIDA BAY
FL
NOAA Chart: 11449 Latitude: 24° 55.5' N ( 24.92500)
USGS Quad: UPPER MATECUMBE KEY Longitude: 80° 37.9' W ( -80.63170)
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.