U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8720214 PUBLICATION DATE: 11/10/2010
Name: DEGAUSSING STRUCTURE, MAYPORT NAVAL STA.
FL
NOAA Chart: 11490 Latitude: 30° 23.8' N ( 30.39670)
USGS Quad: MAYPORT Longitude: 81° 23.7' W ( -81.39500)
To reach the tidal bench marks from the overpass of Atlantic Boulevard (State
Road 10) and Mayport Road (U.S. Highway A1A) on the south side of Mayport, go
north on Mayport Road (U.S. Highway A1A) for 3.62 km (2.25 mi) to the junction
of Mayport Road (U.S. Highway A1A) and Main Street (County Road 101), continue
north on Main Street (County Road 101) for 2.9 km (1.8 mi) to the entrance of
Mayport Naval Station, pass through the check in station and continue north on
Main Street for 0.2 km (0.1 mi) to the junction of Main Street and Moale Avenue,
turn right and go east on Moale Avenue for 1.05 km (.65 mile) to the junction of
Moale Avenue and Baltimore Street, turn left and go north on Baltimore Street
for 1.4 km (0.9 mile) to the end of pavement. The bench marks are located in the
vicinity of Building 1375 and Baltimore Street. The tide gage was attached to a
cable support structure on the south jetty.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 0214 A 1995
DESIGNATION: 872 0214 A
MONUMENTATION: Flange-encased Rod VM#: 13506
AGENCY: National Ocean Service (NOS) IDB PID#: DI9220
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: DI9220
LATITUDE: 30° 23.7' N ( 30.39556) LONGITUDE: 81° 23.6' W ( -81.39333)
The primary bench mark is a flange-encased rod, 23.6 m (77.5 ft) SW of the
center and end of the Baltimore Street, 7.3 m (23.8 ft) SSE of the approximate
centerline of Baltimore Street, 0.6 m (1.8 ft) NE of the SE corner of a 3.0 m x
3.0 m (10.0 ft x 10.0 ft) concrete pad that is around a drainage, and 0.4 m (1.3
ft) NE of a 3-inch PVC witness post. The datum point is accessed through a
5-inch NGS logo cap, recessed 15.2 cm (0.5 ft) below the level of the NOS logo
cap, being the top of a stainless steel rod, driven to refusal at a depth of
12.1 m (39.6 ft) with a NOS logo cap flush with the level of the ground and
Baltimore Street.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8720214 PUBLICATION DATE: 11/10/2010
Name: DEGAUSSING STRUCTURE, MAYPORT NAVAL STA.
FL
NOAA Chart: 11490 Latitude: 30° 23.8' N ( 30.39670)
USGS Quad: MAYPORT Longitude: 81° 23.7' W ( -81.39500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0214 B 1995
DESIGNATION: 872 0214 B
MONUMENTATION: Flange-encased Rod VM#: 13507
AGENCY: National Ocean Service (NOS) IDB PID#: DL5743
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: DL5743
LATITUDE: 30° 23.6' N ( 30.39333) LONGITUDE: 81° 23.8' W ( -81.39611)
The bench mark is a flanged encased rod, located near the entrance to a parking
lot, 54.1 m (177.6 ft) SE of the SE corner of building number 1597, 39.1 m
(128.3 ft) SSW of the SW corner of building number 1556, 30.2 m (99.0 ft) east
of an aluminum light pole, 24.5 m (80.3 ft) SW of an aluminum light pole, 9.4 m
(30.8 ft) east of the SW end of the parking lot, and 1.0 m (3.4 ft) SE of an
aluminum light pole. The datum point is accessed through a 5-inch NGS logo cap,
recessed 6.1 cm (0.2 ft) below the ground, being the top of a stainless steel
rod, driven to refusal at a depth of 13.3 m (43.6 ft), and encased in a 5-inch
logo cap flush with the level of the ground and NAMTD parking lot.
BENCH MARK STAMPING: 0214 C 1995
DESIGNATION: 872 0214 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 13508
AGENCY: National Ocean Service (NOS) IDB PID#: DL5744
SETTING CLASSIFICATION: Concrete foundation OPUS PID#: DL5744
LATITUDE: 30° 23.7' N ( 30.39444) LONGITUDE: 81° 23.7' W ( -81.39583)
The bench mark is a disk set flush in the NW corner of a small concrete
foundation with a high voltage transformer box number 1410 attached, south of a
small red brick building number 1375, about 83.8 m (275.0 ft) north of the
centerline of Baltimore Street, 23.2 m (76.2 ft) north of the approximate center
of a dirt road around a parking lot, 9.9 m (32.4 ft) SE of the SW corner of
building number 1375, and 4.9 m (16.0 ft) east of a north-south chain link fence
line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8720214 PUBLICATION DATE: 11/10/2010
Name: DEGAUSSING STRUCTURE, MAYPORT NAVAL STA.
FL
NOAA Chart: 11490 Latitude: 30° 23.8' N ( 30.39670)
USGS Quad: MAYPORT Longitude: 81° 23.7' W ( -81.39500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 72 81 A10
DESIGNATION: 72 81 A10
MONUMENTATION: Survey disk VM#: 13509
AGENCY: Florida Department of Natural Resources
(FLDNR) IDB PID#: DL5703
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 30° 23.8' N ( 30.39611) LONGITUDE: 81° 23.6' W ( -81.39389)
The bench mark is a disk set in the top of a prefabricated concrete post
recessed (0.1 ft) below the level of the ground, 81.1 m (266.0 ft) north of the
approximate centerline of Baltimore Street, 69.8 m (229.0 ft) east of tidal
bench mark 0214 C 1995, and 1.0 m (3.2 ft) SE of a metal witness post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8720214 PUBLICATION DATE: 11/10/2010
Name: DEGAUSSING STRUCTURE, MAYPORT NAVAL STA.
FL
NOAA Chart: 11490 Latitude: 30° 23.8' N ( 30.39670)
USGS Quad: MAYPORT Longitude: 81° 23.7' W ( -81.39500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: L 324 1970
DESIGNATION: L 324
MONUMENTATION: Bench Mark disk VM#: 13510
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: BC0473
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 30° 23.7' N ( 30.39444) LONGITUDE: 81° 23.8' W ( -81.39667)
The bench mark is a disk set in the top of a round concrete monument projecting
3.0 cm (0.1 ft) above the level of the ground and 30.5 cm (1.0 ft) below the
level of the road, 34.1 m (112.0 ft) west of the south corner of the Fleet
Training Center Building, 8.2 m (27.0 ft) north of the centerline of Baltimore
Street, 0.6 m (2.0 ft) west of the SE corner of a hurricane fence around a fire
fighting training pad, 0.5 m (1.5 ft) west of a metal witness post, and 0.4 m
(1.2 ft) south of the south fence line.
BENCH MARK STAMPING: 4 MAYPORT NAVAL BASE
DESIGNATION: 4 MAYPORT NAVAL BASE
MONUMENTATION: Survey disk VM#: 19273
AGENCY: National Ocean Service (NOS) IDB PID#: BC0470
SETTING CLASSIFICATION: Concrete Monument OPUS PID:
LATITUDE: 30° 23.3' N ( 30.38806) LONGITUDE: 81° 24.7' W ( -81.41167)
The bench mark is a disk set in the top of a concrete post projecting 7.6 cm
(3.0 in) above the level of the ground, 0.2 km (0.1 mi) east along Massey Avenue
from the junction of Manley Avenue, 16.3 m (53.5 ft) NW of the center of the
intersection of Massey Avenue and Main Street, 13.9 m (45.5 ft) north of the
center line of Massey Avenue, 11.9 m (39.2 ft) west of the approximate center of
Main Street, 0.9 m (3.0 ft) NE of a 15.2 cm (6.0 in) pipe which projects 0.9 m
(3.0 ft) above the ground and painted yellow, and about level with the
intersection.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8720214 PUBLICATION DATE: 11/10/2010
Name: DEGAUSSING STRUCTURE, MAYPORT NAVAL STA.
FL
NOAA Chart: 11490 Latitude: 30° 23.8' N ( 30.39670)
USGS Quad: MAYPORT Longitude: 81° 23.7' W ( -81.39500)
T I D A L D A T U M S
Tidal datums at DEGAUSSING STRUCTURE, MAYPORT NAVAL STA. based on:
LENGTH OF SERIES: 6 MONTHS
TIME PERIOD: May 1998 - October 1998
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8720220 MAYPORT (FERRY DEPOT), SAINT JOHNS RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.613
MEAN HIGH WATER MHW = 1.513
North American Vertical Datum NAVD88 = 0.969
MEAN SEA LEVEL MSL = 0.782
MEAN TIDE LEVEL MTL = 0.782
MEAN LOW WATER MLW = 0.049
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
0214 A 1995 2.808 1.295
0214 B 1995 3.391 1.878
0214 C 1995 4.564 3.051
72 81 A10 4.611 3.098
L 324 1970 2.785 1.272
4 MAYPORT NAVAL BASE 4.245 2.732
Foot Notes:
Geodetic heights of the bench marks meet all NOAA/NOS/NGS quality control
standards for Second Order, Class 1 leveling. It is advised that a confirmation
set of levels be established for bench mark 4 MAYPORT NAVAL BASE to verify
height differences before using tidal bench mark elevation information.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8720214 PUBLICATION DATE: 11/10/2010
Name: DEGAUSSING STRUCTURE, MAYPORT NAVAL STA.
FL
NOAA Chart: 11490 Latitude: 30° 23.8' N ( 30.39670)
USGS Quad: MAYPORT Longitude: 81° 23.7' W ( -81.39500)
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.