U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 9446484 PUBLICATION DATE: 09/22/2017
Name: TACOMA, COMMENCEMENT BAY
WA
NOAA Chart: 18453 Latitude: 47° 16.0' N ( 47.26667)
USGS Quad: TACOMA NORTH Longitude: 122° 24.8' W (-122.41333)
To reach the tidal bench marks proceed west about 5 km (3 mi) from the
intersection of exit 136 of Interstate I-5 and Port of Tacoma Road, turn left
onto 11th Street and proceed 0.5 km (0.3 mi), turn right, just before the
bridge, into the Port of Tacoma Administration Building. The bench marks are in
the vicinity of the Port of Tacoma Administration Building. The tide station is
located on the north side of the building at the eastern end of Pier 7.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6484 A 1996
DESIGNATION: 944 6484 A
MONUMENTATION: Tidal Station disk VM#: 13310
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 47° 15.9' N ( 47.26497) LONGITUDE: 122° 24.8' W (-122.41314)
The primary bench mark is a disk located in a dirt area between the east end of
the Port of Tacoma observation tower and the parking lot, 2.41 m (7.9 ft) east
of stairway leading to the top of the tower, 1.25 m (4.1 ft) south of the
southernmost of two 1.67 m (5.5 ft) tall decorative lights, and 0.49 m (1.6 ft)
north of a concrete wall surrounding the tower. The bench mark is set 15 cm (0.5
ft) below grade, crimped to a stainless steel rod driven 30.5 m (100 ft) to
refusal, and is encased in a PVC pipe with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 9446484 PUBLICATION DATE: 09/22/2017
Name: TACOMA, COMMENCEMENT BAY
WA
NOAA Chart: 18453 Latitude: 47° 16.0' N ( 47.26667)
USGS Quad: TACOMA NORTH Longitude: 122° 24.8' W (-122.41333)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6484 C 1996
DESIGNATION: 944 6484 C
MONUMENTATION: Tidal Station disk VM#: 13312
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete slab OPUS PID:
LATITUDE: 47° 16.0' N ( 47.26686) LONGITUDE: 122° 24.7' W (-122.41158)
The bench mark is a disk set in the concrete loading dock at the west end of
Pier 7 at 2205 Sitcom way, 6.25 m (20.5 ft) west of the east end of the dock,
6.25 m (20.5 ft) south of a large sliding door, 0.30 m (1.0 ft) north of south
end of loading dock, and 1 m (3 ft) above ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 9446484 PUBLICATION DATE: 09/22/2017
Name: TACOMA, COMMENCEMENT BAY
WA
NOAA Chart: 18453 Latitude: 47° 16.0' N ( 47.26667)
USGS Quad: TACOMA NORTH Longitude: 122° 24.8' W (-122.41333)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: TIDE 22 1933
DESIGNATION: TIDAL 22
MONUMENTATION: Tidal Station disk VM#: 13315
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: SY0536
SETTING CLASSIFICATION: Concrete slab OPUS PID:
LATITUDE: 47° 15.9' N ( 47.26494) LONGITUDE: 122° 24.7' W (-122.41175)
The bench mark is a disk set in a 1 x 1 m (3 x 3 ft) concrete slab of the NW
sidewalk at the NE end of East 11 Street bridge over Puyallup River, 2.80 m (9.2
ft) NW of the curb of the Street, 1.10 m (3.6 ft) NW of a decorative pillar,
0.61 m (2.0 ft) NE of the SW edge of the concrete slab, and 0.30 m (1.0 ft)
above the street level.
BENCH MARK STAMPING: 6484 D 2007
DESIGNATION: 944 6484 D
MONUMENTATION: Metal Rod VM#: 18296
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 47° 16.0' N ( 47.26631) LONGITUDE: 122° 24.6' W (-122.41078)
The bench mark is located at the Port of Tampa near terminal 7 on the west side
of Sitcum Way inside a landscaped area surrounded by concrete curb, 10.35 m
(34.0 ft) east of the middle of the railroad track section at switch number 2,
9.20 m (30.2 ft) west of the middle of Sitcum Way, 3.60 m (11.8 ft) north of the
railroad sign, and 1.40 m (4.6 ft) west of the east curb of the planter. The
bench mark is crimped to a stainless steel rod driven 9.8 m (32.2 ft), and
encased in a PVC pipe with aluminum access cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 9446484 PUBLICATION DATE: 09/22/2017
Name: TACOMA, COMMENCEMENT BAY
WA
NOAA Chart: 18453 Latitude: 47° 16.0' N ( 47.26667)
USGS Quad: TACOMA NORTH Longitude: 122° 24.8' W (-122.41333)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6484 E 2007
DESIGNATION: 944 6484 E
MONUMENTATION: Bench Mark disk VM#: 18297
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Handicap ramp OPUS PID:
LATITUDE: 47° 16.0' N ( 47.26689) LONGITUDE: 122° 24.6' W (-122.41056)
The bench mark is set in a concrete wheelchair ramp at the SW corner of building
207 at the Port of Tacoma, 11.90 m (39.0 ft) north of the NW corner of the truck
scale, 8.53 m (28.0 ft) south of the NW corner of the building, 2.28 m (7.5 ft)
west of the SW corner of the building, and 0.30 m (1.0 ft) above ground.
BENCH MARK STAMPING: 6484 F 2016
DESIGNATION: 944 6484 F
MONUMENTATION: Flange-encased Rod VM#: 21858
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBFL74
LATITUDE: 47° 16.0' N ( 47.26744) LONGITUDE: 122° 24.5' W (-122.40914)
The bench mark is a 9/16 inch (14 mm) stainless steel rod driven 99 ft (30.2 m)
to refusal on the N side of Sitcum road, W of the t with Kaiser road, in the
port of Tacoma, located 30.8 m (101.0 ft) E of railroad tracks crossing Sitcum
road, 26.7 m (87.6 ft) W of centerline of Kaiser road, and 0.53 m (1.7 ft) N of
N curb of Sitcum road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 9446484 PUBLICATION DATE: 09/22/2017
Name: TACOMA, COMMENCEMENT BAY
WA
NOAA Chart: 18453 Latitude: 47° 16.0' N ( 47.26667)
USGS Quad: TACOMA NORTH Longitude: 122° 24.8' W (-122.41333)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6484 G 2016
DESIGNATION: 944 6484 G
MONUMENTATION: Flange-encased Rod VM#: 21859
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 47° 16.1' N ( 47.26814) LONGITUDE: 122° 24.5' W (-122.40783)
The bench mark is a 9/16 inch (14 mm) stainless steel rod driven 56 ft (17.1 m)
to refusal on the S side of Sitcum road at the intersection with port center
road and inside the Y formed by two railroad tracks in the port of Tacoma,
located 21.3 m (69.9 ft) E of power pole TP 38695, 20.5 m (67.3 ft) W of the
extended centerline of port center road, and 15.2 m (49.9 ft) S of centerline of
Sitcum road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 9446484 PUBLICATION DATE: 09/22/2017
Name: TACOMA, COMMENCEMENT BAY
WA
NOAA Chart: 18453 Latitude: 47° 16.0' N ( 47.26667)
USGS Quad: TACOMA NORTH Longitude: 122° 24.8' W (-122.41333)
T I D A L D A T U M S
Tidal datums at TACOMA, COMMENCEMENT BAY based on:
LENGTH OF SERIES: 18 YEARS
TIME PERIOD: January 1999 - December 2016
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9447130 SEATTLE, PUGET SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (12/17/2012) = 4.532
MEAN HIGHER HIGH WATER MHHW = 3.589
MEAN HIGH WATER MHW = 3.323
MEAN TIDE LEVEL MTL = 2.094
MEAN SEA LEVEL MSL = 2.085
MEAN LOW WATER MLW = 0.866
North American Vertical Datum NAVD88 = 0.729
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (11/26/2007) = -1.441
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
6484 A 1996 5.137 1.814
6484 C 1996 6.122 2.799
TIDE 22 1933 5.838 2.515
6484 D 2007 5.210 1.887
6484 E 2007 5.422 2.099
6484 F 2016 5.246 1.923
6484 G 2016 5.177 1.854
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 9446484 PUBLICATION DATE: 09/22/2017
Name: TACOMA, COMMENCEMENT BAY
WA
NOAA Chart: 18453 Latitude: 47° 16.0' N ( 47.26667)
USGS Quad: TACOMA NORTH Longitude: 122° 24.8' W (-122.41333)
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.