U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 08/15/1983
Station ID: 8725417 SUPERCEDED DATE: 04/21/2003
Name: CAPTIVA ISLAND, PINE ISLAND SOUND
FLORIDA
NOAA Chart: 11426 Latitude: 26° 31.3' N
USGS Quad: CAPTIVA Longitude: 82° 11.3' W
To reach the tidal bench marks from Sanibel on Sanibel Island, 90 west and north
on FL 867 to Captiva Island, continuing on the Andys Fishing Camp on Pine Island
Sound. The bench marks are near the boat harbor and Hudson Street, and tide
gage was on Andys Fishing Pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: BM 1 1961
MONUMENTATION: Survey Disk VM#: 7331
AGENCY: PID#: AG1670
SETTING CLASSIFICATION: Concrete Post
The bench mark is near Andys Fishing Pier, set on top of a concrete post
projecting 0.2 foot (0.1 m) near the NW corner of an abandoned concrete
foundation leading west from the boat slip about level with Palm Avenue, 225
feet (68.6 m) SW of the west end of the fishing pier, 104 feet (31.7 m) NE of
the Back steps of a white frame house, 102 feet (31.1 m) south of the centerline
of Palm Avenue, 83 feet (25.3 m) west of the NW corner of a boat slip, 43 feet
(8.3 m) south of the SE corner of a house, and 27.5 feet (8.4 m) west of the SW
corner of a boat repair shed.
BENCH MARK STAMPING: BM 3 1961
MONUMENTATION: Survey Disk VM#: 7332
AGENCY: PID#: AG1668
SETTING CLASSIFICATION: Concrete Step
The bench mark is set 1 foot (0.3 m) above ground level in top of the east end
of the bottom step of the west entrance of Green Covered framehouse, 252 feet
(76.8 m) south of the centerline of Palm Avenue, 150 feet (45.7 m) south of
Bench Mark BM 1 1961, and 20.5 feet (6.2 m) WNW of the NE corner of the house.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 08/15/1983
Station ID: 8725417 SUPERCEDED DATE: 04/21/2003
Name: CAPTIVA ISLAND, PINE ISLAND SOUND
FLORIDA
NOAA Chart: 11426 Latitude: 26° 31.3' N
USGS Quad: CAPTIVA Longitude: 82° 11.3' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Y 241 1965
MONUMENTATION: Survey Disk VM#: 7333
AGENCY: PID#: AG1667
SETTING CLASSIFICATION: Iron Pipe
The bench mark is set on top of a protective 4-inch iron pipe which projects 0.1
foot (0.03 m) above ground, 0.05 mile (0.08 km) east along Coconut Drive from
the post office, 65.9 feet (20.1 m) NE from the center of the junction of
Coconut Drive and Munson Street going north, 45.6 feet (13.9 m) west of the SW
corner of Timmys Creek Nook (and Sinclair Station), 33.4 feet (10.2 m) east of
the centerline of the street, and 1.5 feet (0.5 m) south of a power pole. The
bench mark is set on top of an iron pipe driven 45 feet (13.7 m) into the ground
and level with Munson Street.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 08/15/1983
Station ID: 8725417 SUPERCEDED DATE: 04/21/2003
Name: CAPTIVA ISLAND, PINE ISLAND SOUND
FLORIDA
NOAA Chart: 11426 Latitude: 26° 31.3' N
USGS Quad: CAPTIVA Longitude: 82° 11.3' W
T I D A L D A T U M S
Tidal datums at CAPTIVA ISLAND, PINE ISLAND SOUND based on:
LENGTH OF SERIES: 13 MONTHS
TIME PERIOD: APRIL 1965 - MAY 1966
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8725110 NAPLES
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (09/09/1965) = 3.74
MEAN HIGHER HIGH WATER MHHW = 2.04
MEAN HIGH WATER MHW = 1.75
MEAN TIDE LEVEL MTL = 1.08
NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 0.48
MEAN LOW WATER MLW = 0.40
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (02/05/1966) = -1.13
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
BM 1 1961 3.94 2.19
BM 3 1961 3.96 2.21
Y 241 1965 3.93 2.18
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 08/15/1983
Station ID: 8725417 SUPERCEDED DATE: 04/21/2003
Name: CAPTIVA ISLAND, PINE ISLAND SOUND
FLORIDA
NOAA Chart: 11426 Latitude: 26° 31.3' N
USGS Quad: CAPTIVA Longitude: 82° 11.3' 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 (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 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.