NOAA Web Site Link Tides and Currents Home Page Transparent placeholder image

On Saturday, June 23rd, 2018 starting at 7:30 a.m to 8 p.m. EDT, there will be a system maintenance performed affecting the Tides and Currents web site (https://tidesandcurrents.noaa.gov). During this time, the Tides and Currents website will be running with limited capabilities. Click here for more information.

Bench Mark Sheet for 8731439, Gulf Shores, ICWW AL

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  6

                                                                                
Station ID: 8731439                         PUBLICATION DATE:  08/19/2010
Name:       GULF SHORES, ICWW                                 
            AL
NOAA Chart: 11376                           Latitude:   30° 16.8' N (  30.27989)
USGS Quad:  GULF SHORES                     Longitude:  87° 41.1' W ( -87.68428)


To reach the station from Hwy 98 and Hwy 59 in Foley, Al turn left on 59 and
proceed 6.2 miles to the bridge over the ICW and the light. Before going over
the bridge at the light and E 29th St turn left on 29th and then right on 1st
Ave and head towards LuLu's restaurant and the station is at the corner of the
fuel docks.  The bench marks are located in the vicinity of the tide station.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  1439 A 2008
                         DESIGNATION:          873 1439 A

MONUMENTATION:           Tidal Station disk                    VM#:        18961
AGENCY:                  National Ocean Survey/Service(NOS)    IDB PID#:        
SETTING CLASSIFICATION:  Concrete cap                          OPUS PID:        
LATITUDE:   30° 16.8' N (  30.27989)          LONGITUDE:  87° 41.1' W ( -87.68431)


The bench mark is a disk set flush in the concrete cap of the bulkhead located
in the the SE corner of the Valvtect fuel docks near the NOAA tidal station,
35.94 m (117.9 ft) east of the west end of the concrete cap, 4.71 m (15.5 ft)
north of the south corner of the bulkhead, and 0.44 m (1.4 ft) SW of the outside
corner of the concrete cap.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                                                
Station ID: 8731439                         PUBLICATION DATE:  08/19/2010
Name:       GULF SHORES, ICWW                                 
            AL
NOAA Chart: 11376                           Latitude:   30° 16.8' N (  30.27989)
USGS Quad:  GULF SHORES                     Longitude:  87° 41.1' W ( -87.68428)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  1439 B 2008
                         DESIGNATION:          873 1439 B

MONUMENTATION:           Tidal Station disk                    VM#:        18962
AGENCY:                  National Ocean Survey/Service(NOS)    IDB PID#:        
SETTING CLASSIFICATION:  Foundation for fuel tank              OPUS PID:        
LATITUDE:   30° 16.8' N (  30.28003)          LONGITUDE:  87° 41.1' W ( -87.68433)


The bench mark is a disk set flush in the NE corner of a concrete pad for a fuel
tank for the valvtect fuel dock, 26.39 m (86.6 ft) east of the east side of a
white freezer, 23.61 m (77.5 ft) SW of the centerline of the entrance road to
the back lot of Lulu's, 10.67 m (35.0 ft) North of the south corner of the
concrete pad.



                         BENCH MARK STAMPING:  1439 C 2008
                         DESIGNATION:          873 1439 C

MONUMENTATION:           See descriptive text                  VM#:        18963
AGENCY:                  National Ocean Survey/Service(NOS)    IDB PID#:        
SETTING CLASSIFICATION:  Concrete floor                        OPUS PID:        
LATITUDE:   30° 16.8' N (  30.28006)          LONGITUDE:  87° 41.1' W ( -87.68494)


The bench mark is a disk set flush in concrete floor located inside the
restaurant near the double entrance doors, SE of the hostess counter, 6.06 m
(19.9 ft) WSW of the men's room door, 2.58 m (8.5 ft) SSW of the double entrance
doors, and 0.64 m (2.1 ft) NE of a wall.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                                                
Station ID: 8731439                         PUBLICATION DATE:  08/19/2010
Name:       GULF SHORES, ICWW                                 
            AL
NOAA Chart: 11376                           Latitude:   30° 16.8' N (  30.27989)
USGS Quad:  GULF SHORES                     Longitude:  87° 41.1' W ( -87.68428)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  1439 D 2008
                         DESIGNATION:          873 1439 D

MONUMENTATION:           Tidal Station disk                    VM#:        18964
AGENCY:                  National Ocean Survey/Service(NOS)    IDB PID#:        
SETTING CLASSIFICATION:  Concrete cap                          OPUS PID:        
LATITUDE:   30° 16.8' N (  30.28072)          LONGITUDE:  87° 41.1' W ( -87.68539)


The bench mark is a disk set flush in the concrete on bulkhead cap on the SE
side of the marina, north of the volley vall courts, 21.64 m (71.0 ft) NW of the
NW corner of the laundry building, 16.47 m (54.0 ft) NE of the SW corner of the
bulkhead, 3.89 m (12.8 ft) north of a 1.38 m (4.53 ft) high concrete block wall
around the volleyball court and 0.33 m (1.1 ft) SE of the face of the concrete
cap.



                         BENCH MARK STAMPING:  1439 E 2008
                         DESIGNATION:          873 1439 E

MONUMENTATION:           Tidal Station disk                    VM#:        18965
AGENCY:                  National Ocean Survey/Service(NOS)    IDB PID#:        
SETTING CLASSIFICATION:  Concrete cap                          OPUS PID:        
LATITUDE:   30° 16.8' N (  30.28072)          LONGITUDE:  87° 41.1' W ( -87.68492)


The mark is a disk set flush inside the SE corner of the bulkhead in a concrete
cap, 14.77 m (48.5 ft) east of the east corner of the bathroom building, 3.31 m
(10.9 ft) SW of the centerline of a gangway ramp to the southernmost floating
dock, and 2.10 m (6.9 ft) NW of the SE concrete block retaining wall.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                                                
Station ID: 8731439                         PUBLICATION DATE:  08/19/2010
Name:       GULF SHORES, ICWW                                 
            AL
NOAA Chart: 11376                           Latitude:   30° 16.8' N (  30.27989)
USGS Quad:  GULF SHORES                     Longitude:  87° 41.1' W ( -87.68428)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  1439 F 2010
                         DESIGNATION:          873 1439 F

MONUMENTATION:           Survey disk                           VM#:        19666
AGENCY:                  National Ocean Survey/service (NOS)   IDB PID#:        
SETTING CLASSIFICATION:  Concrete cap                          OPUS PID#: BBBV39
LATITUDE:   30° 16.9' N (  30.28207)          LONGITUDE:  87° 41.1' W ( -87.68492)


The bench mark is a disk set flush in the concrete cap at the north end of
Homeport Marina 32.65 m (107.1 ft) west of the center of the gang way ramp
leading to floating dock 'C', 21.18 m (69.5 ft) east of the center of the
gangway ramp leading to floating dock 'B', and 2.59 m (8.5 ft) south of concrete
block retaining wall.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                                                
Station ID: 8731439                         PUBLICATION DATE:  08/19/2010
Name:       GULF SHORES, ICWW                                 
            AL
NOAA Chart: 11376                           Latitude:   30° 16.8' N (  30.27989)
USGS Quad:  GULF SHORES                     Longitude:  87° 41.1' W ( -87.68428)


                            T I D A L   D A T U M S 


Tidal datums at GULF SHORES, ICWW based on:

     LENGTH OF SERIES:      1 YEAR
     TIME PERIOD:           March 2009 - February 2010
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8735180 DAUPHIN ISLAND, MOBILE BAY


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     HIGHEST OBSERVED WATER LEVEL (11/10/2009)         =  1.248
     MEAN HIGHER HIGH WATER                     MHHW   =  0.371
     MEAN HIGH WATER                            MHW    =  0.356
     MEAN TIDE LEVEL                            MTL    =  0.190
     MEAN SEA LEVEL                             MSL    =  0.182
     MEAN LOW WATER                             MLW    =  0.023
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (02/05/2009)         = -0.467

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     1439 A 2008                                 1.394    1.038
     1439 B 2008                                 3.194    2.838
     1439 C 2008                                 3.235    2.879
     1439 D 2008                                 1.716    1.360
     1439 E 2008                                 1.705    1.349
     1439 F 2010                                 1.696    1.340


Foot Notes:

Bench mark 1439 F 2010 is based on one differential leveling connection and does
not meet the quality control standards of the NOS.  Therefore, caution should be
used when deriving elevations for this mark.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  6

                                                                                
Station ID: 8731439                         PUBLICATION DATE:  08/19/2010
Name:       GULF SHORES, ICWW                                 
            AL
NOAA Chart: 11376                           Latitude:   30° 16.8' N (  30.27989)
USGS Quad:  GULF SHORES                     Longitude:  87° 41.1' W ( -87.68428)


                             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.

Return to Top
Products available at 8731439 Gulf Shores, ICWW, AL

Revised: 10/15/2013
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services