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Pacific Coastal and Marine Science Center

R/V Parke Snavely

Photo of Parke Snavely.

Parke D. Snavely, Jr.

Bow view of Snavely in Santa Cruz Harbor; click for larger version.

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

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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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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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) [Full-size image (268 kb)]

Photo of the mini-sparker; click for larger version.

Minisparker on the floor of our Marine Facility in Santa Cruz, CA [Full-size image (68 kb)]

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 [Full-size image (160 kb)]

Photo of an ADCP.

Example of an ADCP

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:

Systems used on Snavely

Snavely Specifications

Heavy-duty A-frame


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Power and fuel

Electrical systems and generator

Electronics and navigation aids

Pilot house with low profile forward berth

Helm and operation station

Cabin interior layout and equipment

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Cabin heat

Head (bathroom)

Plumbing (potable)

Other pumps

Vessel lighting and operation


Vessel meets or exceeds all ABYC and USCG requirements

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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.

SwathPlus bathymetric map example.

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

Illustration of how multibeam sonar works.

Cartoon illustrating the multibeam sonar “swath”

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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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

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 crew hauling camera sled back onto boat; click for arger version.

Crew hauling camera sled back on boat
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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 Riegl Laser Scanner.

Riegl laser scanner, in use on land

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

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

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 Woods Hole Coastal and Marine Science Center 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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url mapping/Snavely.html
last modified 2009