U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8723350 PUBLICATION DATE: 04/01/2004
Name: RAGGED KEY #3
FL
NOAA Chart: 11462 Latitude: 25° 32.0' N ( 25.53330)
USGS Quad: SOLDIER KEY Longitude: 80° 10.3' W ( -80.17170)
To reach the tidal bench marks from Elliott Key Harbor, proceed by boat 7.6 km
(4.7 mi) north to red day beacon 2, then 2.6 km (1.6 mi) NE passing on the north
side of green day beacon 5 to Ragged Key No. 3. The bench marks are located on
or within a circular sea wall. The tide gage and staff were located on the SSW
side of the sea wall.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1971
DESIGNATION: 872 3350 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 5812
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 25° 32.0' N ( 25.53330) LONGITUDE: 80° 10.3' W ( -80.17170)
The primary bench mark is a disk set flush on top of a concrete sea wall which
encircles a two-story house and several small storage buildings, 49.38 m (162.0
ft) north of the SE corner of the sea wall, 23 m (76 ft) ESE of the SE corner of
the house, 21 m (69 ft) west of the east edge of the water line, and 4.85 m
(15.9 ft) NE of a small cement storage building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8723350 PUBLICATION DATE: 04/01/2004
Name: RAGGED KEY #3
FL
NOAA Chart: 11462 Latitude: 25° 32.0' N ( 25.53330)
USGS Quad: SOLDIER KEY Longitude: 80° 10.3' W ( -80.17170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 2 1971
DESIGNATION: 872 3350 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 5813
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 25° 32.0' N ( 25.53330) LONGITUDE: 80° 10.3' W ( -80.17170)
The bench mark is a disk set flush in the concrete sea wall, 21.70 m (71.2 ft)
WNW of the NW corner of the two-story house, 16.15 m (53.0 ft) south of the NW
corner of the sea wall, and 14.33 m (47.0 ft) west of the SW corner of a small
generator building.
BENCH MARK STAMPING: NO 3 1971
DESIGNATION: 872 3350 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 5814
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete flagpole base OPUS PID:
LATITUDE: 25° 32.0' N ( 25.53330) LONGITUDE: 80° 10.3' W ( -80.17170)
The bench mark is a disk set flush in the fourth step of the concrete flagpole
base, 24.51 m (80.4 ft) south of the south wall of the two-story house, 14 m (46
ft) north of a V in the sea wall, and 6.83 m (22.4 ft) west of the west edge of
the boat slip.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8723350 PUBLICATION DATE: 04/01/2004
Name: RAGGED KEY #3
FL
NOAA Chart: 11462 Latitude: 25° 32.0' N ( 25.53330)
USGS Quad: SOLDIER KEY Longitude: 80° 10.3' W ( -80.17170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 4 1974
DESIGNATION: 872 3350 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 5815
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 25° 32.0' N ( 25.53330) LONGITUDE: 80° 10.3' W ( -80.17170)
The bench mark is a disk set flush in the SE corner of the concrete sea wall, 47
m (155 ft) south of bench mark NO 1 1971, 30.33 m (99.5 ft) east of a boat slip,
and 1.62 m (5.3 ft) north of the SE corner of the sea wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8723350 PUBLICATION DATE: 04/01/2004
Name: RAGGED KEY #3
FL
NOAA Chart: 11462 Latitude: 25° 32.0' N ( 25.53330)
USGS Quad: SOLDIER KEY Longitude: 80° 10.3' W ( -80.17170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 872 3350 COMPASS
ALIAS: NO STAMPING 1
MONUMENTATION: See descriptive text VM#: 5816
AGENCY: Unknown IDB PID#:
SETTING CLASSIFICATION: Concrete patio OPUS PID:
LATITUDE: 25° 32.0' N ( 25.53330) LONGITUDE: 80° 10.3' W ( -80.17170)
The bench mark is a brass compass rose set flush in a concrete patio, 19.48 m
(63.9 ft) SSW of bench mark NO 2 1971, 6.19 m (20.3 ft) SW of the corner of the
two-story house, 5.97 m (19.6 ft) WSW of the west corner of the caretakers
house, 5.58 m (18.3 ft) SW of the south corner of the generator building, and
5.27 m (17.3 ft) west of the cistern steps.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8723350 PUBLICATION DATE: 04/01/2004
Name: RAGGED KEY #3
FL
NOAA Chart: 11462 Latitude: 25° 32.0' N ( 25.53330)
USGS Quad: SOLDIER KEY Longitude: 80° 10.3' W ( -80.17170)
T I D A L D A T U M S
Tidal datums at RAGGED KEY #3 based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: January 1975 - December 1975
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 (11/02/1975) = 0.984
MEAN HIGHER HIGH WATER MHHW = 0.567
MEAN HIGH WATER MHW = 0.544
MEAN TIDE LEVEL MTL = 0.293
MEAN SEA LEVEL MSL = 0.288
MEAN LOW WATER MLW = 0.041
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (04/05/1981) = -0.216
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 1 1971 1.573 1.029
NO 2 1971 1.499 0.955
NO 3 1971 1.958 1.414
NO 4 1974 1.573 1.029
872 3350 COMPASS 1.455 0.911
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8723350 PUBLICATION DATE: 04/01/2004
Name: RAGGED KEY #3
FL
NOAA Chart: 11462 Latitude: 25° 32.0' N ( 25.53330)
USGS Quad: SOLDIER KEY Longitude: 80° 10.3' W ( -80.17170)
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.