U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 04/30/1984
Station ID: 9445683 SUPERCEDED DATE: 04/21/2003
Name: POINT JEFFERSON, PUGET SOUND
WASHINGTON
NOAA Chart: 18446 Latitude: 47° 44.7' N
USGS Quad: SHILSHOLE BAY Longitude: 122° 28.6' W
To reach the tidal bench marks from President Point on Puget Sound, Washington
proceed south on President Point Road to the Naval Degaussing Station, 0.5 miles
(0.8 km) north of Point Jefferson. The bench marks are in the vicinity of the
Naval Operations Building. The tide gage was mounted inside the Degaussing
Station perimeter with the tubing and office extending offshore. The tide staff
was free standing adjacent to the office.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 3 1942
MONUMENTATION: Survey Disk VM#: 9074
AGENCY: PID:
SETTING CLASSIFICATION: Retaining Wall
The bench mark is located at the Naval Degaussing Station on Puget Sound, set in
top of a retaining wall on east side of Naval Operations Building, 15 feet (4.6
m) north of the garage entrance, and at the base of a flight of stairs.
BENCH MARK STAMPING: GOOSE 1941
MONUMENTATION: Survey Disk VM#: 9075
AGENCY: PID#: SY4915
SETTING CLASSIFICATION: Concrete Post
The bench mark is located at the Naval Degaussing Station on Puget Sound, north
of Point Jefferson, 16 feet (4.9 m) west of a 20 foot (6.1 m) bluff overlooking
the beach, and set in a concrete post projecting 0.3 foot (0.1 m) above ground
level at the SE corner of the Naval operations building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 04/30/1984
Station ID: 9445683 SUPERCEDED DATE: 04/21/2003
Name: POINT JEFFERSON, PUGET SOUND
WASHINGTON
NOAA Chart: 18446 Latitude: 47° 44.7' N
USGS Quad: SHILSHOLE BAY Longitude: 122° 28.6' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 4 1942
MONUMENTATION: Survey Disk VM#: 9076
AGENCY: PID:
SETTING CLASSIFICATION: Granite Boulder
The bench mark is located at the Naval Degaussing Station on Puget Sound, set in
top of a large boulder 7 feet (2.1 m) in diameter, 24 feet (7.3 m) west of main
entrance steps to building on the west side of the Naval Operations Building, 3
feet (1.0 m) above ground level.
BENCH MARK STAMPING: 5683 A
MONUMENTATION: Survey Disk VM#: 9077
AGENCY: PID:
SETTING CLASSIFICATION: Shallow Set Pipe
The bench mark is at the Naval Degaussing Station north of Point Jefferson, in a
grassy area at the NE gate to the parking area, 10.0 feet (3.0 m) west of the
east face of the rock retaining wall, in a line with the north fence of the
degaussing station, projecting 2 inches (0.1 m) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 04/30/1984
Station ID: 9445683 SUPERCEDED DATE: 04/21/2003
Name: POINT JEFFERSON, PUGET SOUND
WASHINGTON
NOAA Chart: 18446 Latitude: 47° 44.7' N
USGS Quad: SHILSHOLE BAY Longitude: 122° 28.6' W
T I D A L D A T U M S
Tidal datums at POINT JEFFERSON, PUGET SOUND based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: MARCH-MAY 1978
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 9447130 SEATTLE
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (03/08/1978) = 12.11
MEAN HIGHER HIGH WATER MHHW = 10.83
MEAN HIGH WATER MHW = 9.97
MEAN TIDE LEVEL MTL = 6.37
MEAN LOW WATER MLW = 2.77
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (05/23/1978) = -2.89
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
NO 3 1942 35.24 25.27
GOOSE 1941 35.43 25.46
NO 4 1942 45.33 35.36
5683 A 17.75 7.78
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 04/30/1984
Station ID: 9445683 SUPERCEDED DATE: 04/21/2003
Name: POINT JEFFERSON, PUGET SOUND
WASHINGTON
NOAA Chart: 18446 Latitude: 47° 44.7' N
USGS Quad: SHILSHOLE BAY Longitude: 122° 28.6' 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.