U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
Station ID: 9454951 PUBLICATION DATE: 04/26/2011
Name: KINGS BAY INSIDE, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16705 Latitude: 60° 27.4' N ( 60.45670)
USGS Quad: SEWARD B-5 Longitude: 148° 39.9' W (-148.66500)
To reach the bench marks, go to the SW end of Kings Bay, on the NW end of Kings
Point.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4951 A 1997
MONUMENTATION: Tidal Station disk VM#: 13840
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 60° 27.4' N ( 60.45670) LONGITUDE: 148° 39.9' W (-148.66500)
The primary bench mark is a disk set flush in bedrock, the southern most of
three marks, surrounded by three depressions in the rock that form poinds of
standing water, 40 m (131 ft) south of bench mark 4951 B 1997, approximately 20
m (66 ft) east of the apparent high water line and 20 m (66 ft) NE of the
southern high point of Kings Point.
BENCH MARK STAMPING: 4951 B 1997
MONUMENTATION: Tidal Station disk VM#: 13850
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 60° 27.4' N ( 60.45670) LONGITUDE: 148° 39.9' W (-148.66500)
The bench mark is a disk set flush in bedrock, the middle mark of three marks,
15 m (49 ft) SE of a crevice running NW to SE through the rock, 40 m (131 ft)
north of bench mark 4951 A 1997, 15 m (49 ft) south of the northern-most high
point of Kings Point, and 15 m (49 ft) east of the top of the cliff face of
Kings Point.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
Station ID: 9454951 PUBLICATION DATE: 04/26/2011
Name: KINGS BAY INSIDE, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16705 Latitude: 60° 27.4' N ( 60.45670)
USGS Quad: SEWARD B-5 Longitude: 148° 39.9' W (-148.66500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4951 C 1997
MONUMENTATION: Tidal Station disk VM#: 13851
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Rock OPUS PID:
LATITUDE: 60° 27.4' N ( 60.45670) LONGITUDE: 148° 39.9' W (-148.66500)
The bench mark is a disk set flush in rock on the northern tip of Kings Point,
the northern most of three marks, on the west edge of a large crevice running
north to south, 70 m (230 ft) NE of bench mark 4951 B 1997, 13 m (43 ft) east of
the top western edge of the point, and 10 m (33 ft) south of the apparent high
water line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
Station ID: 9454951 PUBLICATION DATE: 04/26/2011
Name: KINGS BAY INSIDE, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16705 Latitude: 60° 27.4' N ( 60.45670)
USGS Quad: SEWARD B-5 Longitude: 148° 39.9' W (-148.66500)
T I D A L D A T U M S
Tidal datums at KINGS BAY INSIDE, PRINCE WILLIAM SOUND based on:
LENGTH OF SERIES: 43 DAYS
TIME PERIOD: September 10 1997 - October 22 1997
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9454240 VALDEZ, PRINCE WILLIAM SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 3.759
MEAN HIGH WATER MHW = 3.477
MEAN SEA LEVEL MSL = 2.022
MEAN TIDE LEVEL MTL = 1.977
MEAN LOW WATER MLW = 0.477
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
4951 A 1997 6.224 2.747
4951 B 1997 6.516 3.039
4951 C 1997 5.537 2.060
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
Station ID: 9454951 PUBLICATION DATE: 04/26/2011
Name: KINGS BAY INSIDE, PRINCE WILLIAM SOUND
AK
NOAA Chart: 16705 Latitude: 60° 27.4' N ( 60.45670)
USGS Quad: SEWARD B-5 Longitude: 148° 39.9' W (-148.66500)
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.