U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9449292 PUBLICATION DATE: 07/15/2004
Name: SANDY POINT, LUMMI BAY
WA
NOAA Chart: 18431 Latitude: 48° 47.4' N ( 48.79000)
USGS Quad: LUMMI BAY Longitude: 122° 42.5' W (-122.70800)
To reach the tidal bench marks from Bellingham, proceed NW on Interstate Highway
5 to the Lummi Bay exit, then proceed west on Slater Road for about 11 km (7 mi)
to the end of the road, then turn left and proceed south on Sucia Drive to Sandy
Point. The bench marks are located on and in the vicinity of the property of
Sandy Point Marina. The gage and staff were located on the piling on the ramp
to the floating docks.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: BM 1 1974
DESIGNATION: 944 9292 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 9296
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 48° 47.4' N ( 48.79000) LONGITUDE: 122° 42.5' W (-122.70800)
The primary bench mark is a disk set flush in the concrete base of a retaining
wall on the east end of the concrete slab supporting the overhead boat launch of
the marina, 13 m (42 ft) SE of the gas pumps located on the NW corner of the
concrete slab, and 1 m (3 ft) below the level of the concrete slab.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9449292 PUBLICATION DATE: 07/15/2004
Name: SANDY POINT, LUMMI BAY
WA
NOAA Chart: 18431 Latitude: 48° 47.4' N ( 48.79000)
USGS Quad: LUMMI BAY Longitude: 122° 42.5' W (-122.70800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BM 2 1974
DESIGNATION: 944 9292 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 9297
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete slab OPUS PID:
LATITUDE: 48° 47.4' N ( 48.79000) LONGITUDE: 122° 42.5' W (-122.70800)
The bench mark is a disk set flush in the NW end of the concrete slab supporting
the overhead boat launch of the marina, 11 m (36 ft) WNW of bench mark BM 1
1974, and 2 m (7 ft) east of the gas pumps.
BENCH MARK STAMPING: BM 3 1974
DESIGNATION: 944 9292 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 9298
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footing OPUS PID:
LATITUDE: 48° 47.4' N ( 48.79000) LONGITUDE: 122° 42.5' W (-122.70800)
The bench mark is a disk set flush in the top of a 1 m (2 ft) square concrete
footing supporting the porch pole in the SW corner of the third house north of
the marina along the west side of the paved road and NW of bench mark BM 2 1974.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9449292 PUBLICATION DATE: 07/15/2004
Name: SANDY POINT, LUMMI BAY
WA
NOAA Chart: 18431 Latitude: 48° 47.4' N ( 48.79000)
USGS Quad: LUMMI BAY Longitude: 122° 42.5' W (-122.70800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BM 4 1974
DESIGNATION: 944 9292 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 9299
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete slab OPUS PID:
LATITUDE: 48° 47.5' N ( 48.79170) LONGITUDE: 122° 42.5' W (-122.70800)
The bench mark is a disk set flush in the NE corner of the concrete slab east of
the southernmost garage door of a five door garage WSW of the office, and 49 m
(160 ft) SW of bench mark BM 2 1974.
BENCH MARK STAMPING: BM 5 1974
DESIGNATION: 944 9292 TIDAL 5
MONUMENTATION: Tidal Station disk VM#: 9300
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 48° 47.4' N ( 48.79000) LONGITUDE: 122° 42.5' W (-122.70800)
The bench mark is a disk set flush in the top of the SW end of the concrete
retaining wall along the east end of the rock jetty on the north side of the
channel leading into the marina, and 94 m (310 ft) ESE of bench mark BM 4 1974.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9449292 PUBLICATION DATE: 07/15/2004
Name: SANDY POINT, LUMMI BAY
WA
NOAA Chart: 18431 Latitude: 48° 47.4' N ( 48.79000)
USGS Quad: LUMMI BAY Longitude: 122° 42.5' W (-122.70800)
T I D A L D A T U M S
Tidal datums at SANDY POINT, LUMMI BAY based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: March 1974 - March 1974
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9449424 CHERRY POINT, STRAIT OF GEORGIA
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 2.749
MEAN HIGH WATER MHW = 2.501
MEAN TIDE LEVEL MTL = 1.645
MEAN SEA LEVEL MSL = 1.586
MEAN LOW WATER MLW = 0.789
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
BM 1 1974 3.419 0.918
BM 2 1974 4.312 1.811
BM 3 1974 4.484 1.983
BM 4 1974 4.306 1.805
BM 5 1974 3.988 1.487
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9449292 PUBLICATION DATE: 07/15/2004
Name: SANDY POINT, LUMMI BAY
WA
NOAA Chart: 18431 Latitude: 48° 47.4' N ( 48.79000)
USGS Quad: LUMMI BAY Longitude: 122° 42.5' W (-122.70800)
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.