Report_Great_Kills_Marina_Sonar.pdf

SIDE SCAN SONAR INVESTIGATIONS

GREAT KILLS HARBOR

STATEN ISLAND, NY

Submitted to:

Volkert, Inc.

3809 Moffett Road Mobile, Alabama 36618 by:

Dolan Research, Inc.

30 Paper Mill Road Newtown Square, PA 19073

March 8, 2013

Introduction On 1 March 2013, Dolan Research, Inc. (DR) conducted high-frequency sonar investigations in Great Kills Harbor, Staten Island, New York, to detect and identify any bottom anomalies that may have been deposited during/since the flooding associated with Hurricane Sandy. The defined survey area was a 300-foot wide corridor adjacent to the east and north sides of Great Kills Harbor (Figure 1).

Sonar data were collected offshore across the 300-foot wide corridor that extended for approximately 6,000 feet around the east and north edge of the harbor. Three parallel lanes were completed at 100’ intervals, following the contour of the curved shoreline. The inner two lanes went directly through the maze of pilings associated with the Great Kills Marina. Navigation through this area was possible since all of the floating docks had been removed.

Summary of Field Survey and Equipment Survey operations were conducted from a 24-foot aluminum survey boat. A Marine Sonic HDS all digital side scan sonar system was used to conduct the survey. A dual frequency, 600/1200 kHz, side scan sensor was employed to collect acoustic data. The sonar sensor was towed off the bow of the survey boat in an effort to obtain the most diagnostic acoustic “pictures” of the harbor bottom in the project corridor. Data were collected primarily using a 120’ range and the 600kHz sensor. Marine Sonic data acquisition software was used to merge the acoustic data with real-time positioning data. Data were post-processed using Chesapeake Technology, Inc. software.

Project horizontal reference is the New York (east) State Plane Coordinate System, NAD 83, in feet.

Data Products - Side Scan Sonar The side scan sonar derives its information from reflected acoustic energy. Side looking sonar, which transmits and receives swept high frequency bandwidth signals from transducers mounted on a sensor that is towed from a survey vessel. Two sets of transducers mounted in an array along both sides of the towfish generate the short duration acoustic pulses required for high resolution images. The pulses are emitted in a thin, fan-shaped pattern that spreads downward to either side of the towfish in a plane perpendicular to its path. As the fish is towed along the survey trackline this acoustic beam sequentially scans the bottom from a point beneath the fish outward to each side of the trackline.

Acoustic energy reflected from any bottom discontinuities (exposed pipelines, rocks, boat wrecks, or other obstructions) is received by the set of transducers, amplified and transmitted to the survey vessel via a tow cable. The digital output from state of the art units is essentially analogous to a high angle oblique photograph providing detailed representations of bottom features and characteristics. Sonar allows display of positive relief (features extending above the bottom) and negative relief (such as depressions) in either light or dark opposing contrast modes on a video monitor. Examination of the images thus allows a determination of significant features and objects present on the bottom within a survey area.

Individual acoustic data files were initially examined using Marine Sonic acoustic data review software to identify any unnatural or man-made features in the records. Once identified, acoustic features were described using visible length, width, and height from the bottom surface.

Finally, sonar data files were post-processed using software from Chesapeake Technology and merged into a geo-referenced sonar mosaic that was overlaid onto an aerial photograph of the project area The location of sonar targets were the overlaid onto the sonar mosaic (Figure 2).

Findings Inspection of the sonar data confirmed the presence of 34 potentially significant bottom anomalies within the project corridor. The sonar anomalies were classified according to type:

Debris related (8) Linear debris (8) Boat wreck (17) Former pier (1).

A complete description, including the location coordinates, of all the sonar targets is contained in Table 1, below. A sonar mosaic of the project area was overlaid on an aerial photograph and is presented in Figure 2.

After the coordinates and profiles for these 34 targets have been interfaced with hydrographic data, recommendations can be made regarding the respective hazards of each target to safe navigation. If the elevation profile of any of these features exceeds the minimum depth specifications for Great Kills Harbor, it is recommended they be removed.

Figure 1. Limits of Project Area in Great Kills Harbor, Staten Island, NY

Note: Photograph with survey limits (yellow line) was provided by Volkert, Inc.

34 33

Figure 2. Sonar Mosaic of Great Kills Harbor Project Area

Note: Locations of the 34 sonar contacts are indicated

20 18 15

01 03

Table 1. List of Prominent Sonar Contacts (34) in the Great Kills Harbor Project Area

Contact Info: 01 Comments

• Sonar Time at Target: 03/01/2013 14:10:42

• Click Position (Lat/Lon Coordinates)

40° 32.18330' N 074° 08.37595' W (WGS84)

• Click Position (Projected Coordinates)

(X) 592291.57 (Y) 620508.36

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 2774

• Range to Target: 21.87 US Feet

• Line Name: 2013MAR01_0002

Target Height: =3.0 US Feet Target Length: 30.3 US Feet Target Width: 15.6 US Feet

Description: A pile of debris, 30' x 16' with linear components. Portions of the debris extend 3' above the bottom surface.

Contact Info: 02 Comments

• Sonar Time at Target: 03/01/2013 14:10:46

40° 32.16018' N 074° 08.37636' W (WGS84)

• Click Position (Projected Coordinates)

(X) 592290.26 (Y) 620367.97

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 2826

• Range to Target: 20.23 US Feet

Target Height: =1.1 US Feet Target Length: 4.0 US Feet Target Width: 3.8 US Feet

Description: A 4' square box-like feature that has 1.1' of relief above the surrounding bottom surface.

Contact Info: 03 Comments

• Sonar Time at Target: 03/01/2013 14:14:47

40° 32.20894' N 074° 08.02201' W (WGS84)

• Click Position (Projected Coordinates)

(X) 593930.45 (Y) 620670.76

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 6434

• Range to Target: 11.96 US Feet

Target Height: = 6.0 US Feet Target Length: 15.2 US Feet

Description: A 15' long linear (pile) that extends up off the bottom at a pronounced angle. This feature extends approximately 6' above the bottom surface and is located on the out-shore edge of the marina complex.

Contact Info: 04 Comments

• Sonar Time at Target: 03/01/2013 14:14:58

40° 32.21588' N 074° 08.00839' W (WGS84)

• Click Position (Projected Coordinates)

(X) 593993.34 (Y) 620713.16

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 6590

• Range to Target: 19.38 US Feet

Target Height: = 1.20 US Feet Target Length: 37.5 US Feet

Description: A 37' long linear feature is lying flat on the bottom surface at the outer edge of the marina. This feature is suggestive of a pile from the marina complex.

A rectangular component is attached to one of pile.

Contact Info: 05 Comments

• Sonar Time at Target: 03/01/2013 14:15:17

40° 32.23038' N 074° 07.99103' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594073.42 (Y) 620801.50

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 6853

• Range to Target: 20.24 US Feet

Target Height: = 0.8 US Feet Target Length: 30.4 US Feet Target Width: 8.1 US Feet

Description: Some rectangular debris, 30' x 8' is lying flat on the bottom at the outer edge of the marina. This feature has limited relief above the bottom surface.

Contact Info: 06 Comments

• Sonar Time at Target: 03/01/2013 14:16:51

40° 32.30796' N 074° 07.90503' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594469.81 (Y) 621274.19

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 8165

• Range to Target: 23.96 US Feet

Target Height: = 1.1 US Feet Target Length: 38.1 US Feet

Description: Four linear features are lying flat on the bottom along the outer edge of the marina facility.

These piles have only limited relief above the bottom surface.

Contact Info: 07 Comments

• Sonar Time at Target: 03/01/2013 14:17:18

40° 32.32961' N 074° 07.87947' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594587.64 (Y) 621406.15

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 8565

• Range to Target: 24.36 US Feet

Target Height: = 3.5US Feet Target Length: 17.0 US Feet

Description: A 17' linear feature (suspect pile) that extends up out of the bottom at an angle. One end extends 3.5' above the bottom surface.

Contact Info: 08 Comments

• Sonar Time at Target: 03/01/2013 14:18:17

40° 32.38078' N 074° 07.82410' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594842.83 (Y) 621717.87

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 9405

• Range to Target: 18.54 US Feet

Target Height: = 0.9 US Feet Target Length: 25.4 US Feet Target Width: 4.9 US Feet

Description: A rectangular feature, 15' x 5' is lying flat on the bottom surface.

Contact Info: 09 Comments

• Sonar Time at Target: 03/01/2013 14:18:32

40° 32.39260' N 074° 07.80976' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594908.94 (Y) 621789.92

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 9625

• Range to Target: 19.36 US Feet

Target Height: = 0.9 US Feet Target Length: 36.2 US Feet

Description: A 36' long linear feature is lying flat on the

Contact Info: 10 Comments

• Sonar Time at Target: 03/01/2013 14:19:31

40° 32.44557' N 074° 07.75643' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595154.63 (Y) 622112.61

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 10480

• Range to Target: 16.21 US Feet

Target Height: = 3.4 US Feet Target Length: 15.9 US Feet Target Width: 8.3 US Feet

Description: A 15' x 8' debris pile that has a 3.4' high profile above the bottom surface

Contact Info: 11 Comments

• Sonar Time at Target: 03/01/2013 14:19:48

40° 32.47123' N 074° 07.76324' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595122.40 (Y) 622268.24

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 10705

• Range to Target: 20.17 US Feet

Target Height: = 2.4 US Feet Target Length: 15.5 US Feet Target Width: 7.7 US Feet

Description: A small boat wreck, 16' x 7' in size is lying flat on the bottom with 2.4' of profile above the bottom

Contact Info: 12 Comments

• Sonar Time at Target: 03/01/2013 14:20:21

40° 32.50117' N 074° 07.74151' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595222.31 (Y) 622450.46

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 11184

• Range to Target: 18.17 US Feet

Target Height: = 5.0 US Feet Target Length: 26.9 US Feet Target Width: 10.1 US Feet

Description: Boat wreck, 27' x 10' is lying upright on the bottom surface. Wreck extends more than 5' off the

Contact Info: 13 Comments

• Sonar Time at Target: 03/01/2013 14:22:09

40° 32.61096' N 074° 07.74777' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595190.48 (Y) 623116.89

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 12688

• Range to Target: 13.34 US Feet

Target Height: = 4.1 US Feet Target Length: 24.0 US Feet Target Width: 13.0 US Feet

Description: Cluster of linear debris. Some of the debris extends 4' off the bottom surface

Contact Info: 14 Comments

• Sonar Time at Target: 03/01/2013 14:22:21

40° 32.61498' N 074° 07.76932' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595090.57 (Y) 623140.89

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 12856

• Range to Target: 6.86 US Feet

Target Height: = 2.1 US Feet Target Length: 16.8 US Feet Target Width: 6.5 US Feet

Description: Small boat wreck, 17' x 6', lying upright and flat on the bottom. Feature has approximately 2' of

Contact Info: 15 Comments

• Sonar Time at Target: 03/01/2013 14:25:54

40° 32.74736' N 074° 07.99223' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594054.78 (Y) 623940.33

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 15890

• Range to Target: 5.72 US Feet

Target Height: = 5.1 US Feet Target Length: 22.1 US Feet Target Width: 9.8 US Feet

Description: A boat wreck, 22' x 10', lying upright on the bottom surface. Boat has slightly more than 5' of

Contact Info: 16 Comments

• Sonar Time at Target: 03/01/2013 14:26:57

40° 32.74414' N 074° 08.08571' W (WGS84)

• Click Position (Projected Coordinates)

(X) 593621.91 (Y) 623918.98

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 16820

• Range to Target: 3.72 US Feet

Target Height: = 4.5 US Feet Target Length: 24.7 US Feet Target Width: 9.8 US Feet

Description: Boat wreck, 25' x 10', lying flat on the bottom surface. Wreck has 4.5' of profile off the bottom

Contact Info: 17 Comments

• Sonar Time at Target: 03/01/2013 14:27:29

40° 32.74476' N 074° 08.13602' W (WGS84)

• Click Position (Projected Coordinates)

(X) 593388.88 (Y) 623921.77

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 17308

• Range to Target: 22.86 US Feet

Target Height: = 2.9 US Feet Target Length: 17.2 US Feet

Description: A 17' long linear feature that extends up off the bottom at an acute angle. This feature had 2.9' of relief above the bottom surface.

Contact Info: 18 Comments

• Sonar Time at Target: 03/01/2013 14:25:18

40° 32.74226' N 074° 07.93942' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594299.52 (Y) 623910.36

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0002.sds

• Ping Number: 15358

• Range to Target: 4.77 US Feet

Target Height: = 7.0 US Feet Target Length: 58.3 US Feet Target Width: 14.8 US Feet

Description: Larger boat wreck, 58' x 14', lying upright on the bottom surface. Wreck has at least 7' of profile above the bottom surface. Debris, likely from the boat, has spilled out onto the bottom surface away from the hull.

Contact Info: 19 Comments

• Sonar Time at Target: 03/01/2013 14:32:24

40° 32.70539' N 074° 07.79736' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594958.39 (Y) 623689.26

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0004.sds

• Ping Number: 21601

• Range to Target: 18.55 US Feet

• Line Name: 2013MAR01_0004

Target Height: = 2.8 US Feet Target Length: 10.0 US Feet

Description: A 10' long linear feature that extends up off the bottom surface at an angle. This feature extends 2.8' above the bottom surface.

Contact Info: 20 Comments

• Sonar Time at Target: 03/01/2013 14:30:04

40° 32.77065' N 074° 08.00115' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594012.88 (Y) 624081.53

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0004.sds

• Ping Number: 19449

• Range to Target: 12.40 US Feet

Target Height: = +/- 2.0 US Feet

Description: Remnants of a former pier extends at an angle away from the shoreline. Piles that comprised dolphins have been cut off several feet above the mud line.

Coordinates are provided for the approximate center of the former structure (noted on NOAA charts).

Contact Info: 21 Comments

• Sonar Time at Target: 03/01/2013 14:35:28

40° 32.50728' N 074° 07.71415' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595348.88 (Y) 622488.08

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0004.sds

• Ping Number: 24458

• Range to Target: 13.11 US Feet

Target Height: = 3.0 US Feet Target Length: 18.5 US Feet Target Width: 6.5 US Feet

Description: Feature that appears to be the hull of a small, inverted boat with a length of rope or chain attached to one end. This 18' long feature has a 3' high

Contact Info: 22 Comments

• Sonar Time at Target: 03/01/2013 14:37:06

40° 32.41269' N 074° 07.78989' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595000.48 (Y) 621912.32

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0004.sds

• Ping Number: 25945

• Range to Target: 16.63 US Feet

Target Height: = 2.0 US Feet Target Length: 27.5 US Feet Target Width: 9.3 US Feet

Description: Boat wreck that is lying upright and partially buried in the bottom. This site has 2' profile above the bottom surface.

Contact Info: 23 Comments

• Sonar Time at Target: 03/01/2013 14:49:58

40° 32.12900' N 074° 08.17972' W (WGS84)

• Click Position (Projected Coordinates)

(X) 593201.91 (Y) 620182.39

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 37061

• Range to Target: 7.84 US Feet

• Line Name: 2013MAR01_0006

Target Height: = 3.5 US Feet Target Length: 22.0 US Feet Target Width: 8.0 US Feet

Description: Boat wreck, 22' x 8' that is lying upright on the bottom surface. Located close to rip rap, this feature has 3.5' of profile above the bottom surface

Contact Info: 24 Comments

• Sonar Time at Target: 03/01/2013 14:51:33

40° 32.15007' N 074° 08.04262' W (WGS84)

• Click Position (Projected Coordinates)

(X) 593836.44 (Y) 620312.93

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 38438

• Range to Target: 13.55 US Feet

Target Height: = 3.6 US Feet Target Length: 23.5 US Feet Target Width: 9.3 US Feet

Description: Boat wreck, 23' x 9', is lying upright on the bottom, perpendicular to nearby shoreline. This feature has 3.6' of profile above the bottom surface

Contact Info: 25 Comments

• Sonar Time at Target: 03/01/2013 14:51:55

40° 32.16274' N 074° 08.01467' W (WGS84)

• Click Position (Projected Coordinates)

(X) 593965.62 (Y) 620390.41

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 38747

• Range to Target: 20.72 US Feet

Target Height: = +5.0 US Feet Target Length: 26.2 US Feet Target Width: 8.7 US Feet

Description: Rectangular/oval shaped feature, 26' x 9', that is suggestive of a boat wreck. This feature is lying near the shoreline and has pronounced relief (>5') above the bottom surface.

Contact Info: 26 Comments

• Sonar Time at Target: 03/01/2013 14:53:18

40° 32.22221' N 074° 07.93485' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594333.84 (Y) 620753.03

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 39838

• Range to Target: 22.90 US Feet

Target Height: = 1.5 US Feet Target Length: 15.3 US Feet Target Width: 5.5 US Feet

Description: A rectangular feature, 15' x 5' located next to the bulkhead in the marina. Feature has approximately 1.5' of relief above the bottom surface.

Contact Info: 27 Comments

• Sonar Time at Target: 03/01/2013 14:54:06

40° 32.26285' N 074° 07.89584' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594513.49 (Y) 621000.52

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 40490

• Range to Target: 12.83 US Feet

Target Height: = 0.8 US Feet Target Length: 40.4 US Feet

Description: A 40' long linear feature (pile) that is lying flat on the bottom surface.

Contact Info: 28 Comments

• Sonar Time at Target: 03/01/2013 14:54:31

40° 32.28642' N 074° 07.87998' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594586.38 (Y) 621143.89

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 40818

• Range to Target: 0.19 US Feet

Target Height: = 3.5 US Feet Target Length: 22.3 US Feet Target Width: 7.3 US Feet

Description: Rectangular feature, 22' x 7', is lying flat on the bottom in the marina. This feature has 3.5' of profile above the bottom surface.

Contact Info: 29 Comments

• Sonar Time at Target: 03/01/2013 14:59:57

40° 32.56486' N 074° 07.67787' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595515.42 (Y) 622838.36

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 45150

• Range to Target: 8.80 US Feet

Target Height: = 3.6 US Feet Target Length: 25.1 US Feet Target Width: 11.1 US Feet

Description: Rectangular debris, 25' x 11', suggestive of a partially disarticulated boat hull. One portion of this feature has 3.6' of profile above the bottom surface.

Contact Info: 30 Comments

• Sonar Time at Target: 03/01/2013 15:00:27

40° 32.59891' N 074° 07.66862' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595557.39 (Y) 623045.28

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 45554

• Range to Target: 23.10 US Feet

Target Height: = Visible on Surface Target Length: 20.0 US Feet Target Width: 9.1 US Feet

Description: Boat wreck, 20' x 9', is lying on the bottom next to the Great Kills boat launching ramp. This wreck is partially visible on the surface as low tide.

Contact Info: 31 Comments

• Sonar Time at Target: 03/01/2013 15:00:47

40° 32.61914' N 074° 07.68183' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595495.71 (Y) 623167.84

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 45837

• Range to Target: 17.27 US Feet

Target Height: = +/- 7.0 US Feet Target Length: 21.8 US Feet Target Width: 9.8 US Feet

Description: There are a cluster of bottom features on the north(west) side of the Great Kills boat ramp. One is clearly a 22' x 10' boat wreck which is partially visible on the surface at low tide. Other debris appears to have collected in and around the base of piles on that side of the ramp.

Contact Info: 32 Comments

• Sonar Time at Target: 03/01/2013 15:01:47

40° 32.67584' N 074° 07.71766' W (WGS84)

• Click Position (Projected Coordinates)

(X) 595328.30 (Y) 623511.38

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 46622

• Range to Target: 25.15 US Feet

Target Height: = Partially visible on surface Target Length: 22.9 US Feet Target Width: 8.9 US Feet

Description: Bat wreck is lying up against the bulkhead, northwest of the boat ramp. This boat is partially visible above the water surface.

Contact Info: 33 Comments

• Sonar Time at Target: 03/01/2013 15:05:21

40° 32.80720' N 074° 07.96016' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594201.79 (Y) 624304.22

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 49535

• Range to Target: 33.77 US Feet

Target Height: = +/-4.0 US Feet Target Length: 33.6 US Feet

Description: A 33' long feature is resting against the bulkhead in the north part of the cove. This appears to be the inverted hull of a vessel. Height of the feature is only estimated since it is resting against the bulkhead which effectively blocks its sonar shadow.

Contact Info: 34 Comments

• Sonar Time at Target: 03/01/2013 15:05:35

40° 32.81062' N 074° 07.98249' W (WGS84)

• Click Position (Projected Coordinates)

(X) 594098.27 (Y) 624324.57

• Map Proj: NY83-EF

• Acoustic Source File: I:\Sonar Data\Staten Island\20130301\2013MAR01_0006.sds

• Ping Number: 49733

• Range to Target: 32.51 US Feet

Target Height: = +/-3.0 US Feet Target Length: 20.2 US Feet

Description: A 20' long feature is lying flat on the bottom against the base of the seawall at the north side of the cove. This feature is suggestive of the inverted hull of a boat. Height of the feature is only estimated since it is resting against the bulkhead which effectively blocks its sonar shadow.