U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                                                
Station ID: 8453033                         PUBLICATION DATE:  01/27/2005
Name:       BAY SPRING, BULLOCK COVE                          
            RI
NOAA Chart: 13224                           Latitude:   41° 45.1' N (  41.75170)
USGS Quad:  EAST PROVIDENCE                 Longitude:  71° 21.1' W ( -71.35170)


To reach the tidal bench marks from I-195, take exit 7 and proceed south on
Route 114 for 4.8 km (3.0 mi) to Forbes Street, then west on Forbes Street for
2.3 km (1.4 mi) to Willet Avenue, then south on Willet Avenue for 2.1 km (1.3
mi) to Metropolitan Park Drive (which also has a sign indicating the way to
Haines Park), then south on Metropolitan Park Drive for 1.0 km (0.6 mi) to Cove
Haven Marina.  The bench marks are located on the marina property and across
Metropolitan Park Drive from the Marina entrance. The tide gage and staff were
located on the southermost boat deployment ramp.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  3033 C 1994
                         DESIGNATION:          845 3033 C

MONUMENTATION:           Tidal Station disk                    VM#:        12877
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Building foundation                   OPUS PID:        
LATITUDE:   41° 45.1' N (  41.75170)          LONGITUDE:  71° 21.1' W ( -71.35170)


The primary bench mark is a disk set in the concrete foundation on the SE side
of Building 1 at Cove Haven Marina, 15.36 m (50.4 ft) SW of the NE corner of the
workshop and storage building (Bldg. 1), 15.00 m (49.2 ft) NW of the NW wall of
Bldg. 2, 8.81 m (28.9 ft) NE of the SW side of the Bldg. 1 bay door, and 0.1 m
(0.3 ft) above ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 8453033                         PUBLICATION DATE:  01/27/2005
Name:       BAY SPRING, BULLOCK COVE                          
            RI
NOAA Chart: 13224                           Latitude:   41° 45.1' N (  41.75170)
USGS Quad:  EAST PROVIDENCE                 Longitude:  71° 21.1' W ( -71.35170)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  3033 A 1994
                         DESIGNATION:          845 3033 A

MONUMENTATION:           Tidal Station disk                    VM#:        12878
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete fuel pad                     OPUS PID:        
LATITUDE:   41° 45.1' N (  41.75170)          LONGITUDE:  71° 21.1' W ( -71.35170)


The bench mark is a disk set in the SW area of the Marina on a concrete fuel
pad, 26.49 m (86.9 ft) south of the SW corner of the marina office, 14.81 m
(48.6 ft) WNW of power pole No. 3, 3.81 m (12.5 ft) NNE of a chain link fence,
and level with the ground.



                         BENCH MARK STAMPING:  3033 B 1994
                         DESIGNATION:          845 3033 B

MONUMENTATION:           Tidal Station disk                    VM#:        12879
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete bulkhead                     OPUS PID:        
LATITUDE:   41° 45.1' N (  41.75170)          LONGITUDE:  71° 21.1' W ( -71.35170)


The bench mark is a disk set on the concrete bulkhead at the NW corner of the
marina parking lot, 18.90 m (62.0 ft) north of the ramp leading to the floating
docks, 1.10 m (3.6 ft) SW of a light pole, 0.49 m (1.6 ft) east of the west edge
of the bulkhead, 0.21 m (0.7 ft) above the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 8453033                         PUBLICATION DATE:  01/27/2005
Name:       BAY SPRING, BULLOCK COVE                          
            RI
NOAA Chart: 13224                           Latitude:   41° 45.1' N (  41.75170)
USGS Quad:  EAST PROVIDENCE                 Longitude:  71° 21.1' W ( -71.35170)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  3033 D 1994
                         DESIGNATION:          845 3033 D

MONUMENTATION:           Tidal Station disk                    VM#:        12880
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete ramp to building             OPUS PID:        
LATITUDE:   41° 45.1' N (  41.75170)          LONGITUDE:  71° 21.1' W ( -71.35170)


The bench mark is a disk set in the concrete footing of the storage building
(Bldg. 3), 24.90 m (81.7 ft) SSE of the SW corner of Bldg. 2, 23.90 m (78.4 ft)
WSW of the NE corner of Bldg. 3, 1.71 m (5.6 ft) NNW of NW corner of Bldg. 3,
and level with the ground.



                         BENCH MARK STAMPING:  3033 E 1994
                         DESIGNATION:          845 3033 E

MONUMENTATION:           Tidal Station disk                    VM#:        12881
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   41° 45.1' N (  41.75170)          LONGITUDE:  71° 21.1' W ( -71.35170)


The bench mark is a disk located east of the entrance of Cove Haven Marina,
12.31 m (40.4 ft) east of the centerline of the road (Metropolitan Park
Drive/Narragansett Rd), 6.71 m (22.0 ft) ENE of power pole No. 11, and 4.60 m
(15.1 ft) NE of the NW corner of a fence.  The bench mark is 9 cm (0.3 ft) below
ground level, crimped to a stainless steel rod driven 9.8 m (32 ft) to refusal
and encased in a PVC pipe and concrete kickblock.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 8453033                         PUBLICATION DATE:  01/27/2005
Name:       BAY SPRING, BULLOCK COVE                          
            RI
NOAA Chart: 13224                           Latitude:   41° 45.1' N (  41.75170)
USGS Quad:  EAST PROVIDENCE                 Longitude:  71° 21.1' W ( -71.35170)


                            T I D A L   D A T U M S 


Tidal datums at BAY SPRING, BULLOCK COVE based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           September 1994 - September 1994
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8454000 PROVIDENCE, PROVIDENCE RIVER


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     MEAN HIGHER HIGH WATER                     MHHW   =  1.422
     MEAN HIGH WATER                            MHW    =  1.347
     MEAN TIDE LEVEL                            MTL    =  0.700
     MEAN SEA LEVEL                             MSL    =  0.663
     MEAN LOW WATER                             MLW    =  0.053
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     3033 C 1994                                 4.556    3.209
     3033 A 1994                                 3.760    2.413
     3033 B 1994                                 3.833    2.486
     3033 D 1994                                 4.668    3.321
     3033 E 1994                                 5.202    3.855


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                                                
Station ID: 8453033                         PUBLICATION DATE:  01/27/2005
Name:       BAY SPRING, BULLOCK COVE                          
            RI
NOAA Chart: 13224                           Latitude:   41° 45.1' N (  41.75170)
USGS Quad:  EAST PROVIDENCE                 Longitude:  71° 21.1' W ( -71.35170)


                             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.