U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
Station ID: 8725114 PUBLICATION DATE: 01/06/2004
Name: NAPLES BAY, NORTH
FLORIDA
NOAA Chart: 11429 Latitude: 26° 8.2' N
USGS Quad: NAPLES NORTH Longitude: 81° 47.3' W
To reach the tidal bench marks from the 90 degree bend in U.S. Highway 41 in the
city of Naples, proceed east on U.S. Highway 41 for 0.56 km (0.35 mi) to the
first bridge over the Gordon River, then turn right and proceed south on River
Point Drive to the Naples Sailing and Yacht Club. The bench marks are in the
vicinity of the bridge and Yacht Club. The gage and staff were on a dock on the
south end of the property.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 5114 A 1978
DESIGNATION: 872 5114 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 7893
AGENCY: National Ocean Survey (NOS) PID#: AD6328
SETTING CLASSIFICATION: Concrete manhole cover
The primary bench mark is a disk set flush on the west side of a 1 m x 1 m (3 ft
x 4 ft) concrete manhole cover at the Naples Sailing and Yacht Club, 91 m (300
ft) south of the south side of the pavement of the south bound lane of U.S.
Highway 41, 7.92 m (26.0 ft) west of the centerline of River Point Drive, and
0.3 m (1 ft) SW of the NW corner of the most western lid of the manhole cover.
NOTE: Mark not found in 1990 by US Power Squadron.
BENCH MARK STAMPING: BMT A 47
DESIGNATION: BMT A 47
MONUMENTATION: Survey disk VM#: 7840
AGENCY: LOCSUR PID#: AD6329
SETTING CLASSIFICATION: Concrete sea wall
The bench mark is a disk set in the top of the sea wall on the east side of the
club, 85 m (278 ft) NE of the juntion of the sea wall with the east-west running
sea wall, and (0.8 ft) SW of the NE end of the sea wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
Station ID: 8725114 PUBLICATION DATE: 01/06/2004
Name: NAPLES BAY, NORTH
FLORIDA
NOAA Chart: 11429 Latitude: 26° 8.2' N
USGS Quad: NAPLES NORTH Longitude: 81° 47.3' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BMT B 48
DESIGNATION: BMT B 48
MONUMENTATION: Survey disk VM#: 7841
AGENCY: LOCSUR PID#: AD6330
SETTING CLASSIFICATION: Concrete sea wall
The bench mark is a disk set in the top of the SE end of a concrete sea wall
running NW-SE, 88 m (287 ft) south of bench mark BMT B 48, 15 m (49 ft) south of
the south corner of the yacht club, 15 m (48 ft) east of the SE corner of the
patio, and 0.2 m (0.6 ft) north of the south side of the sea wall.
BENCH MARK STAMPING: BMT C 49
DESIGNATION: BMT C 49
MONUMENTATION: Survey disk VM#: 7842
AGENCY: LOCSUR PID#: AD6331
SETTING CLASSIFICATION: Concrete sea wall
The bench mark is a disk set in the top of a NW-SE running sea wall, 35.97 m
(118.0 ft) north of the south end of the boat pier, 16 m (51 ft) SW of the west
corner of the yacht club, and 13 m (43 ft) SW of a flagpole.
BENCH MARK STAMPING: 14.98
DESIGNATION: 14.98
MONUMENTATION: Survey disk VM#: 7843
AGENCY: Florida State Road Department (FLSRD) PID#: AD1249
SETTING CLASSIFICATION: Concrete bridge rail
The bench mark is a disk set in the top of the north concrete bridge rail of
bridge # 030013, 7.01 m (23.0 ft) north of the center of the westbound lanes of
the highway, 0.21 m (0.7 ft) east of the west end of the north concrete bridge
rail, and 1.2 m (3.9 ft) above highway level. NOTE: The bridge rail is part of
the abutment.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
Station ID: 8725114 PUBLICATION DATE: 01/06/2004
Name: NAPLES BAY, NORTH
FLORIDA
NOAA Chart: 11429 Latitude: 26° 8.2' N
USGS Quad: NAPLES NORTH Longitude: 81° 47.3' W
T I D A L D A T U M S
Tidal datums at NAPLES BAY, NORTH based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: August 1978 - August 1978
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8725110 NAPLES, GULF OF MEXICO
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER (MHHW) = 0.840
MEAN HIGH WATER (MHW) = 0.765
NORTH AMERICAN VERTICAL DATUM-1988 (NAVD) = 0.630
MEAN SEA LEVEL (MSL) = 0.478
MEAN TIDE LEVEL (MTL) = 0.464
MEAN LOW WATER (MLW) = 0.163
MEAN LOWER LOW WATER (MLLW) = 0.000
National Geodetic Vertical Datum (NGVD 29)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
5114 A 1978 2.152 1.387
BMT A 47 1.422 0.657
BMT B 48 1.459 0.694
BMT C 49 1.443 0.678
14.98 4.857 4.092
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
Station ID: 8725114 PUBLICATION DATE: 01/06/2004
Name: NAPLES BAY, NORTH
FLORIDA
NOAA Chart: 11429 Latitude: 26° 8.2' N
USGS Quad: NAPLES NORTH Longitude: 81° 47.3' W
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 (NAVD 88).
NGVD 29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded. NGVD 29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads. NGVD 29 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 NGVD 29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at
National Geodetic Survey.
NAVD 88 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. NAVD 88 replaces NGVD 29 as the national
standard geodetic reference for heights. Bench mark elevations relative to
NAVD 88 are available from NGS through the World Wide Web at
National Geodetic Survey.
NGVD 29 and NAVD 88 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 NAVD 88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD 88 elevations.
The NAVD 88 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, NAVD 88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD 88 elevations listed for
each bench mark in the NGS database.