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R/V Parke Snavely

The USGS Pacific Coastal and Marine Science Center acquired Research Vessel Parke Snavely in November 2007. R/V Snavely is a 34’ Armstrong Catamaran with an open stern and an aluminum hull. Her beam is 10’6” and she drafts 3’9”. She features a self-bailing welded aluminum deck, removeable boarding, port-side dive door, and internal sea chests.

The boat is named after Parke D. Snavely, Jr. (1919 - 2003), a pioneer of marine geology research at USGS.

R/V Snavely is principally a seafloor mapping boat, used in many seafloor and nearshore operations:

  • sonar mapping
  • LiDAR mapping
  • seafloor photography/videography or “ground-truthing”
  • sampling

Systems used on Snavely

The use of brand names is for identification purposes only and does not imply endorsement by the USGS

Bow view of Snavely in Santa Cruz Harbor; click for larger version.
R/V Snavely
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Photo of Parke Snavely.
Parke D. Snavely, Jr.

Snavely Specifications


Heavy-duty A-frame

  • 14’ height
  • 5’ transom clearance for deployment
  • A-frame cylinders unpin and lay forward in nesting position for transport


  • All stainless deck fittings
  • Two Vickers VTM 42 electric clutches (Port main and generator)
  • 20 gallon Hydraulic reservoir
  • Hydraulic cross-over manifold to allow use of either pump online
  • Hydraulic quick disconnect deck fittings for hydraulic winch and auxiliary equipment
  • Kinematics Anchor winch with 300 1/2” Amsteel line /50’ chain with Bruce anchor
  • Kinematics 4” hydraulic cathead
  • Two Davit receptacles (1 port 1 starboard)
  • Armstrong removable Davit (1000 lb. rating with 8’ lift)

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Power and fuel

  • Twin Volvo 310 HP electronic diesel engines
  • Volvo Penta out-drives
  • Electric Volvo controls
  • LCD Volvo Smart management and monitoring
  • Counter-rotating Nybril Props
  • Roxul engine room sound proofing
  • Racor external fuel filter system for engines and generator
  • Two 120-gallon welded aluminum fuel tanks

Electrical systems and generator

  • Westerbeke 12kW Marine diesel generator
  • 30 amp AC shore power system
  • Heart 5000 W inverter and battery charger
  • Path Maker smart switching system to direct charge and manual bypass
  • Two Group 3 1 high output starting batteries
  • One 8-D Deep cycle house battery
  • Blue Seas AC/DC 16 circuit breaker panel
  • Two 12v Marino power outlets (one dash/one computer station)
  • Six Dual 110v AC GFI protected outlets (1 galley,1 dinette, 2 electronic rack, 2 helm)

Electronics and navigation aids

  • Autopilot: Simrad AP26 Series Auto Pilot and pump
  • Radar: Furuno Model 1824 C 2.2 kW Radar and Chart Plotter
  • Depth Sounder: Garmin thru-hull transducer with NMEA output
  • VHF Radios: 2 Icom 602 VHF radios with direct select calling
  • Two Conrad VHF antennas

Pilot house with low profile forward berth

  • 12’ L x 8’ W welded aluminum pilot house cabin with 6’3” headroom

Helm and operation station

  • Auxiliary Helm string station on aft deck

Cabin interior layout and equipment

  • Microwave oven
  • Port side dinette table for science/observers with internet LAN, USB hub
  • 72” long starboard side science data acquisition station:
    • Three 27” flat screen monitor work stations
    • Two Navigation/acquisition computers
    • One data processing computer (for port side dinette station)
    • 72” long electronic systems shelf
    • 8” electronics deck cable pass through to aft deck in starboard aft bulkhead

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Cabin heat

  • Flagship MAC 18000 BTU air conditioner/ heating

Head (bathroom)

  • Stand-up toilet compartment with wash basin
  • Fresh water deck shower

Plumbing (potable)

  • 40 gallon freshwater tank (50 unavailable)
  • AC and Engine hot water tank and system
  • Hot water to galley, head, & buck deck
  • On-demand electric fresh water pump

Other pumps

  • Four 2000 gph bilge pumps with (auto/manual)
  • Two Vickers Hydraulic pumps
  • One Pacer high capacity sea water deck wash down pump

Vessel lighting and operation

  • Hella 40 Navigation lights
  • Two High Power remote operated Spot lights
  • One Aft deck work flood lamp
  • Electric horn
  • Ritchie B-80 compass


  • Three-axle NovaTek aluminum 5th Wheel Gooseneck Galvanized Trailer (30,000 GVW)
  • Electric over hydraulic disc brakes

Vessel meets or exceeds all ABYC and USCG requirements

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Photo of the A-frame with Morro Rock in distance; click for larger version.
View of the A-frame “in action”, with Morro Rock in distance
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Bow of Snavely; click for larger version.
Bow of Snavely showing the anchor
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Snavely, aft; click for larger version.
Snavely's stern out of the water, showing the engines and props
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Port side dive door; click for larger version.
PCMSC Marine Electronics Technician Mike Boyle adjusting gear and rigging aboard R/V Snavely; opened dive door in foreground
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Photo of the aft deck showing the auxiliary helm string station; click for larger version.
Auxiliary helm string station on aft deck
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Photo of the pilot house; click for larger version.
Pilot house
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Snavely on San Francisco Bay; click for larger version.
Snavely on San Francisco Bay
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Snavely in Nisqually Delta, Puget Sound; click for larger version.
Snavely in Nisqually Delta, Puget Sound
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Snavely on its trailer; click for larger version.
Snavely on its trailer, parked at the PCMSC Marine Facility in Santa Cruz, CA
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Systems used on Snavely


Submetrix SwathPlus

SwathPlus is a combination swath bathymetry and side-scan system that creates a 3-dimensional image of the seafloor topography and a backscatter “picture”. The swath width is 10 to 15 times the water depth, and it works in relatively shallow water (up to 100 meters water depth). For example, in an area with a water depth of 20 meters, the swath could be 200 meters wide. By collecting a series of closely spaced parallel lines, we build up a 3-dimensional picture of the seafloor.

Illustration of how multibeam sonar works.
Cartoon illustrating the multibeam sonar “swath”

SwathPlus bathymetric map example.
Color-coded bathymetry, offshore Santa Barbara, CA, derived from the SwathPlus hull-mounted interferometric system

SwathPlus on its boom off the starboard side of Snavely; click for larger version.
SwathPlus in background on its boom off starboard side of Snavely
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SwathPlus up close; click for larger version
Close-up of SwathPlus
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Reson multibeam sonar

The Reson is a “multibeam” echosounder that operates much like the SwathPlus, except that it will work in deeper water (up to 600 meters water depth).


EdgeTech Chirp sub-bottom cross-section sonar

The Chirp sub-bottom profiler creates a two-dimensional image of the material beneath the seafloor like a cross-section under the ship trackline, to a depth of tens of meters.

Example of Chirp data.
Example of Chirp cross-section data from a PCMSC research cruise

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Photograph of the Chirp; click for a larger version.
Chirp sub-bottom cross-section sonar (big, yellow fish) sitting aboard Snavely, next to “Maggie” the magnetometer (used to measure the strength and/or direction of the magnetic field)
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Minisparker sub-bottom cross-section sonar

Minisparker sub-bottom profiler works very much like the Chirp, but the cross-section it can produce is much deeper, up to hundreds of meters beneath the seafloor, depending on the materials. Minisparker can penetrate deeper in softer material such as silt and mud; penetration is less in hard rock.

Example of minisparker data.
Example of Minisparker data from a PCMSC research cruise

Photo of the mini-sparker; click for larger version.
Minisparker on the floor of our Marine Facility in Santa Cruz, CA
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Photo of the mini-sparker stowed and ready for use aboard Snavely; click for larger version.
Minisparker coiled up and stowed, ready to deploy, aboard Snavely
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Acoustic doppler current profiler

The ADCP transducer assembly, composed of 4 transducers (red circles in the photograph), transmits acoustic pulses along two pairs of orthogonal beams (4 beams total). Pulses reflected from scatterers in the water column are received by the ADCP and converted into eastward, northward, and vertical components of water flow using the Doppler Effect and basic trigonometry.

Example of ADCP data output.
Example of ADCP data from a PCMSC research cruise

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Photo of an ADCP.
Example of an ADCP

Camera sled with still-photo and video cameras

The camera sled is a frame equipped with underwater still-photo (color and black & white) and video cameras, towed behind the boat just above the seafloor. The camera sled takes pictures of the seafloor and the plants and animals living there. The pictures and videos are used for “ground-truthing” the seafloor, or relating image data from systems like the multibeam sonar to real features and materials on the seafloor.

Backscatter image of the seafloor with two example photos that prove the backscatter data.
Example of video observations over backscatter imagery and corresponding seafloor photographs
The red dots on the map indicate observations of sediment (sand or mud), while blue dots indicate observations of hard ground (rock, boulder). The photograph taken at the hard ground observation (top) with high backscatter shows a seafloor of boulders and red gorgonia. The photograph taken at a sediment observation (bottom) with lower backscatter shows a seafloor covered in sands with white sea urchins and an octopus.

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Photo of crew hauling camera sled back onto boat; click for arger version.
Crew hauling camera sled back on boat
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Riegl Laser Scanner

PCMSC will mount a Riegl laser scanner atop Snavely to create 3D LiDAR maps of coastal land from the boat. Pictured here is PCMSC's terrestrial scanner similar to the one that will be mounted on Snavely.

Example of LiDAR data of coastal bluffs in Pleasure Point, Santa Cruz, CA

Photo of Riegl Laser Scanner.
Riegl laser scanner, in use on land

Benthos Stingray ROV

The Stingray is a small, modular ROV that can be configured for a wide range of inspection and light work task operations. It can be fitted with cameras (video and still), navigation, and manipulators that allow the driver to collect various samples. PCMSC recently used the Stingray to collect samples at tar and gas seeps off of Santa Barbara.

The Stingray is on loan from our sister team, the USGS Science Center for Coastal and Marine Geology in Woods Hole, MA.

Gerry Hatcher preparing the ROV for sampling work.
Gerry Hatcher preparing the Stingray ROV
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Jonathan Borden driving the ROV
Jonathan Borden, from the USGS Science Center for Coastal and Marine Geology in Woods Hole, MA, driving the ROV
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Photo of the bottom of the ocean, as the camera sees it.
Photo of gas bubbles escaping from seafloor, up past a sample funnel; fish can be seen swimming nearby
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Stingray ROV aboard Snavely.
The Stingray ROV aboard Snavely, equipped with various cameras, sensors, and sampling devices
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Tom Lorenson holding a tar ball.
Tom Lorenson inspecting a sticky, stringy tar ball stuck on the Stingray ROV
Full-size image (200 kb)

The use of brand names is for identification purposes only and does not imply endorsement by the USGS


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Page Contact Information: Laura Zink Torresan
Page Last Modified: 30 November 2011 (lzt)