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

                                                                                
Station ID: 8761927                         PUBLICATION DATE:  04/16/2018
Name:       USCG NEW CANAL STA., LAKE PONTCHARTRAIN           
            LA
NOAA Chart: 11369                           Latitude:   30°  1.6' N (  30.02722)
USGS Quad:  SPANISH FORT                    Longitude:  90°  6.8' W ( -90.11333)


To reach the station from the junction of Interstate Highway 10 and Causeway
Boulevard, go north for 0.55 km (0.35 mi) on Causeway Boulevard to Veterans
Memorial Highway.  Turn right and go east for 3.89 km (2.40 mi) on Veterans
Memorial Boulevard to Ponchatrain Boulevard.  Turn left and go north for 1.85 km
(1.15 mi) on Ponchatrain Boulevard to Robert E Lee Boulevard.  Countinue
straight ahead and go north for 0.72 km (0.45 mi) on Robert E. Lee Boulevard to
the New Canal Lighthouse Museum on the left at the east end of a curve in the
road.  Turn left onto a narrow lane for 30 m (98.4 ft) to the station on the
right.


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


                 PRIMARY BENCH MARK STAMPING:  ALCO 1931
                         DESIGNATION:          ALCO

MONUMENTATION:           Tidal Station disk                    VM#:          832
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  BJ1342
SETTING CLASSIFICATION:  Sea wall                              OPUS PID#: BJ1342
LATITUDE:   30°  1.6' N (  30.02694)          LONGITUDE:  90°  6.8' W ( -90.11278)


The primary bench mark is a disk set in the top of the sea wall near the Coast
Guard Station, 35.0 m (114.8 ft) east of the west end of the sea wall, 34.0 m
(111.5 ft) NW of the center line of Lakeshore Drive, and 21.0 m (68.9 ft) east
of a steel fence corner post on top of the sea wall.

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

                                                                                
Station ID: 8761927                         PUBLICATION DATE:  04/16/2018
Name:       USCG NEW CANAL STA., LAKE PONTCHARTRAIN           
            LA
NOAA Chart: 11369                           Latitude:   30°  1.6' N (  30.02722)
USGS Quad:  SPANISH FORT                    Longitude:  90°  6.8' W ( -90.11333)


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


                         BENCH MARK STAMPING:  ALCO 1931 RM
                         DESIGNATION:          ALCO RM

MONUMENTATION:           Reference Mark disk                   VM#:          831
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  BJ1344
SETTING CLASSIFICATION:  Sea wall                              OPUS PID#:       
LATITUDE:   30°  1.6' N (  30.02678)          LONGITUDE:  90°  6.8' W ( -90.11317)


The bench mark is a disk set flush in the top of a seawall, located along the
south shore of Lake Pontchartrain, 27.31 m (89.60 ft) west of triangulation
station ALCO, 20.91 m (68.60 ft) south of the SE corner of a lighthouse at 800
Lakeshore Drive, 3.29 m (10.79 ft) west of the center of the south entrance gate
for the lighthouse, and 0.49 m (1.61 ft) east of the east of a chain link fence.



                         BENCH MARK STAMPING:  1927 D 2005
                         DESIGNATION:          876 1927 D

MONUMENTATION:           Tidal Station disk                    VM#:        17995
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Sea wall                              OPUS PID:        
LATITUDE:   30°  1.6' N (  30.02700)          LONGITUDE:  90°  6.7' W ( -90.11203)


The bench mark is a disk set in the sea wall along Lake Ponchatrain, due south
of the Jetty Point, 36.49 (119.7 ft) north of Lakeshore Drive, 25.00 m (82.02
ft) NE of the most western light pole in the parking area, and 0.17 m (0.56 ft)
from the edge of the sea wall.

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

                                                                                
Station ID: 8761927                         PUBLICATION DATE:  04/16/2018
Name:       USCG NEW CANAL STA., LAKE PONTCHARTRAIN           
            LA
NOAA Chart: 11369                           Latitude:   30°  1.6' N (  30.02722)
USGS Quad:  SPANISH FORT                    Longitude:  90°  6.8' W ( -90.11333)


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


                         BENCH MARK STAMPING:  1927 E 2005
                         DESIGNATION:          876 1927 E

MONUMENTATION:           Tidal Station disk                    VM#:        17996
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Sea wall                              OPUS PID:        
LATITUDE:   30°  1.6' N (  30.02731)          LONGITUDE:  90°  6.6' W ( -90.11039)


The bench mark is a disk set flush in the seawall along Lake Ponchatrain, 27.25
m (89.40 ft) WNW of light pole "HU8," 24.74 m (81.17 ft) from Lakeshore Drive
and the point of the Jetty bears 320.



                         BENCH MARK STAMPING:  1927 G 2006
                         DESIGNATION:          876 1927 G

MONUMENTATION:           Tidal Station disk                    VM#:        18271
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Sea wall                              OPUS PID:        
LATITUDE:   30°  1.6' N (  30.02714)          LONGITUDE:  90°  6.7' W ( -90.11117)


The bench mark is a disk set flush along the seawall located 143.26 m (470.01
ft) north of the centerline of Lakeshore Drive, 83.52 m (274.02 ft) east of
bench mark 876 1927 D, 19.51 m (64.01 ft) NW of a slighty more distant lightpole
with no number, and 11.89 m (39.01 ft) NNE of a nearby lightpole with no number.

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

                                                                                
Station ID: 8761927                         PUBLICATION DATE:  04/16/2018
Name:       USCG NEW CANAL STA., LAKE PONTCHARTRAIN           
            LA
NOAA Chart: 11369                           Latitude:   30°  1.6' N (  30.02722)
USGS Quad:  SPANISH FORT                    Longitude:  90°  6.8' W ( -90.11333)


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


                         BENCH MARK STAMPING:  1927 H 2006
                         DESIGNATION:          876 1927 H

MONUMENTATION:           Flange-encased Rod                    VM#:        18272
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod in sleeve         OPUS PID:        
LATITUDE:   30°  1.6' N (  30.02703)          LONGITUDE:  90°  6.6' W ( -90.11011)


The bench mark is a flange-encased rod located 101.19 m (331.99 ft) SE of
benchmark 876 1927 G, 17.37 m (56.99 ft) WSW of a nearby light pole, 12.19 m
(39.99 ft) south of centerline of Lakeshore Drive, 9.45 m (31.0 ft) NW of the
centerline of the main entrance to Shelter No. 1, and 1.52 m (4.99 ft) south of
a light pole and witness post. The datum point is stainless steel rod driven
27.4 m (89.9 ft) to refusal in a sleeve extending to a depth of 0.91 m (2.99 ft)
and encased in a 5 inch PVC pipe and concrete kickblock.  Note-sleeve depth does
not meet the specifications for a class A rod mark.

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

                                                                                
Station ID: 8761927                         PUBLICATION DATE:  04/16/2018
Name:       USCG NEW CANAL STA., LAKE PONTCHARTRAIN           
            LA
NOAA Chart: 11369                           Latitude:   30°  1.6' N (  30.02722)
USGS Quad:  SPANISH FORT                    Longitude:  90°  6.8' W ( -90.11333)


                            T I D A L   D A T U M S 


Tidal datums at USCG NEW CANAL STA., LAKE PONTCHARTRAIN based on:

     LENGTH OF SERIES:      7 YEARS
     TIME PERIOD:           1/10 - 12/12, 3/13 - 2/17
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8761305 SHELL BEACH, LAKE BORGNE


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

     HIGHEST OBSERVED WATER LEVEL (08/30/2012)         =  1.985
     MEAN HIGHER HIGH WATER                     MHHW   =  0.164
     MEAN HIGH WATER                            MHW    =  0.164
     MEAN SEA LEVEL                             MSL    =  0.084
     MEAN TIDE LEVEL                            MTL    =  0.081
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     MEAN LOW WATER                             MLW    = -0.002
     LOWEST  OBSERVED WATER LEVEL (12/25/1989)         = -0.792

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     ALCO 1931                                   1.839    1.675
     ALCO 1931 RM                                1.740    1.576
     1927 D 2005                                 1.857    1.693
     1927 E 2005                                 1.878    1.714
     1927 G 2006                                 1.901    1.737
     1927 H 2006                                 1.412    1.248


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

                                                                                
Station ID: 8761927                         PUBLICATION DATE:  04/16/2018
Name:       USCG NEW CANAL STA., LAKE PONTCHARTRAIN           
            LA
NOAA Chart: 11369                           Latitude:   30°  1.6' N (  30.02722)
USGS Quad:  SPANISH FORT                    Longitude:  90°  6.8' W ( -90.11333)


                             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.