U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 7 Station ID: 8724493 PUBLICATION DATE: 04/21/2003 Name: BOCA CHICA MARINA FL NOAA Chart: 11445 Latitude: 24° 34.5' N ( 24.57500) USGS Quad: BOCA CHICA KEY Longitude: 81° 42.5' W ( -81.70830) To reach the tidal bench marks from gate No. 2 at the Boca Chica Naval Air Station, proceed south on a black-topped road for 1.0 km (0.6 mi) to the Boca Chica Marina. The bench marks are in the vicinity of the marina and along the road. The tide gauge was located along the bulkhead near the picnic area. T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 7 Station ID: 8724493 PUBLICATION DATE: 04/21/2003 Name: BOCA CHICA MARINA FL NOAA Chart: 11445 Latitude: 24° 34.5' N ( 24.57500) USGS Quad: BOCA CHICA KEY Longitude: 81° 42.5' W ( -81.70830) T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: N 329 1970 DESIGNATION: N 329 MONUMENTATION: Bench Mark disk VM#: 16097 AGENCY: National Geodetic Survey (NGS) IDB PID#: AA0086 SETTING CLASSIFICATION: Concrete base of manhole OPUS PID: LATITUDE: 24° 34.3' N ( 24.57170) LONGITUDE: 81° 42.2' W ( -81.70330) The primary bench mark is a disk set on top of the west side of a 2x2 m (7x7 ft) concrete base with large iron manhole cover, near the west end of the east-west runway at Boca Chica Naval Air Station, 94 m (307 ft) north of the extended centerline of the east-west runway, 6.71 m (22.0 ft) west of the centerline of the north-south street, 0.12 m (0.4 ft) east of the west edge of the base, 0.09 m (0.3 ft) above the ground level and level with the street.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 7 Station ID: 8724493 PUBLICATION DATE: 04/21/2003 Name: BOCA CHICA MARINA FL NOAA Chart: 11445 Latitude: 24° 34.5' N ( 24.57500) USGS Quad: BOCA CHICA KEY Longitude: 81° 42.5' W ( -81.70830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: H 329 1970 DESIGNATION: H 329 MONUMENTATION: Bench Mark disk VM#: 16098 AGENCY: National Geodetic Survey (NGS) IDB PID#: AA0070 SETTING CLASSIFICATION: Loading platform OPUS PID: LATITUDE: 24° 34.9' N ( 24.58170) LONGITUDE: 81° 42.8' W ( -81.71330) The bench mark is a disk set on top of the east end of the loading ramp along the north side of building No. A 1116 at the weapons storage area at Boca Chica Naval Air Station, 49.96 m (163.9 ft) east of bench mark J 329 1970, 6.86 m (22.5 ft) NW of the NE corner of the building, 4 m (12 ft) north of the north face of the building, 0.18 m (0.6 ft) south of the north edge of platform, 0.15 m (0.5 ft) west of the east end of the ramp, and 1.07 m (3.5 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 7 Station ID: 8724493 PUBLICATION DATE: 04/21/2003 Name: BOCA CHICA MARINA FL NOAA Chart: 11445 Latitude: 24° 34.5' N ( 24.57500) USGS Quad: BOCA CHICA KEY Longitude: 81° 42.5' W ( -81.70830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: J 329 1970 DESIGNATION: J 329 MONUMENTATION: Bench Mark disk VM#: 16099 AGENCY: National Geodetic Survey (NGS) IDB PID#: AA0069 SETTING CLASSIFICATION: Concrete step OPUS PID: LATITUDE: 24° 34.9' N ( 24.58170) LONGITUDE: 81° 42.8' W ( -81.71330) The bench mark is a disk set on the top of the north end of the top step of 5 steps leading to top of loading dock for building A 1116, at the weapons storage area at Boca Chica Naval Air Station, 5 m (18 ft) east of the NW corner of the building, 1.10 m (3.6 ft) north of the north face of the building, 0.3 m (1 ft) south of the north end of the step, and 0.82 m (2.7 ft) above ground level. BENCH MARK STAMPING: 4499 M 2000 DESIGNATION: 872 4499 M MONUMENTATION: Tidal Station disk VM#: 16100 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete bulkhead OPUS PID: LATITUDE: 24° 34.5' N ( 24.57500) LONGITUDE: 81° 42.5' W ( -81.70830) The bench mark is a disk set in top of a concrete bulkhead at Boca Chica Marina at Boca Chica Naval Air Station, about 0.64 km (0.40 mi) from gate No. 2 along a black-topped road, 29.87 m (98.0 ft) NW of the NE corner of Building No. 1132, 16.30 m (53.5 ft) NE of the SW corner of the bulkhead, and 2.60 m (8.53 ft) SE of the NW corner of the bulkhead.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 7 Station ID: 8724493 PUBLICATION DATE: 04/21/2003 Name: BOCA CHICA MARINA FL NOAA Chart: 11445 Latitude: 24° 34.5' N ( 24.57500) USGS Quad: BOCA CHICA KEY Longitude: 81° 42.5' W ( -81.70830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4499 N 2000 DESIGNATION: 872 4499 N MONUMENTATION: Tidal Station disk VM#: 16101 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Manhole foundation OPUS PID: LATITUDE: 24° 34.4' N ( 24.57330) LONGITUDE: 81° 42.3' W ( -81.70500) The bench mark is a disk set in a large concrete foundation for a manhole near a pump station at Boca Chica Naval Air Station, 0.72 km (0.45 mi) along a black topped road from gate No.2, 9.64 m (31.6 ft) NE of the NE corner of Building No.1103, and 8.80 m (28.9 ft) NNW of the NE corner of Building No.1332. BENCH MARK STAMPING: 4499 P 2000 DESIGNATION: 872 4499 P MONUMENTATION: Tidal Station disk VM#: 16102 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Large utility foundation OPUS PID: LATITUDE: 24° 34.3' N ( 24.57170) LONGITUDE: 81° 42.3' W ( -81.70500) The bench mark is set in a large concrete foundation at Boca Bhica Naval Air Station, about 0.72 km (0.45 mi) from gate No.2 along a black-topped road at the intersection of two black-topped roads, 30.78 m (101.0 ft) SSW of a transformer, 5.35 m (17.6 ft) SW of the SW corner of the concrete sign foundation, 3.19 m (10.5 ft) SE of the west corner of the concrete foundation.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 7 Station ID: 8724493 PUBLICATION DATE: 04/21/2003 Name: BOCA CHICA MARINA FL NOAA Chart: 11445 Latitude: 24° 34.5' N ( 24.57500) USGS Quad: BOCA CHICA KEY Longitude: 81° 42.5' W ( -81.70830) T I D A L D A T U M S Tidal datums at BOCA CHICA MARINA based on: LENGTH OF SERIES: 3 Months TIME PERIOD: March 2000 - May 2000 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8724580 KEY WEST Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: North American Vertical Datum NAVD88 = 0.438 MEAN HIGHER HIGH WATER MHHW = 0.381 MEAN HIGH WATER MHW = 0.305 MEAN SEA LEVEL MSL = 0.200 MEAN TIDE LEVEL MTL = 0.178 MEAN LOW WATER MLW = 0.052 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW N 329 1970 1.224 0.919 H 329 1970 2.901 2.596 J 329 1970 2.764 2.459 4499 M 2000 1.776 1.471 4499 N 2000 2.039 1.734 4499 P 2000 1.355 1.050
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 7 of 7 Station ID: 8724493 PUBLICATION DATE: 04/21/2003 Name: BOCA CHICA MARINA FL NOAA Chart: 11445 Latitude: 24° 34.5' N ( 24.57500) USGS Quad: BOCA CHICA KEY Longitude: 81° 42.5' W ( -81.70830) 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.