Thunder Bay Exploration 2002

Operations

Vessels

R/V CONNECTICUT
The R/V CONNECTICUT is a 76' steel hull, single screw, diesel powered research vessel, outfitted for year-round coastal and near continental shelf service. Built by Washburn and Doughty Associates, Inc., East Boothbay, Maine, the vessel was launched in July 1998 and is home ported at the Marine Sciences & Technology Center in Groton, CT.

The ship features wet and dry laboratory spaces. Science vans up to 20' in length can be placed on the large work deck and a full suite of deck machinery is available to perform a wide variety of oceanographic tasks. It has a dynamic positioning system to allow precise ROV operations on shipwrecks.

R/V SHENEHON
NOAA's R/V SHENEHON will serve as the support vessel, e.g., shuttling personnel and supplies to the CONNECTICUT, along with providing a dive platform.

ROV Operations

Scientists will use Remotely Operated Vehicles (ROV) to collect videotape and still images. ROV dives will average approximately 4 hours, but may run longer. It is anticipated that the ship will conduct at least 2 launch and recoveries each day. ROV operations will last no longer than 12 hours within a 24 hour period.

Mystic Aquarium & Institute for Exploration will provide the following equipment:

LITTLE HERCULES
LITTLE HERCULES (also called LITTLE HERC) is a remotely operated vehicle with a color still camera, acoustic altimeter (echosounder), sophisticated vehicle control, a scanning sonar and lighting system.

ARGUS
ARGUS is a towed fiber-optic vehicle that has an array of visual and acoustic sensors, including 3-chip color video cameras, color still cameras, a digital still camera, high-powered HM1 lights, a scanning sonar, and altimeter. It also has powerful thrusters and sophisticated controls and sensors to maintain automatic depth and heading control.

ARGUS and LITTLE HERCULES are designed to operate together. Thrusters (electric motors with propellers) on ARGUS allow the pilot to aim its lights and cameras toward sites of interest and LITTLE HERCULES.

Acoustic Imaging

As time allows, the expedition team will use ECHO to collect additional sidescan sonar data to supplement images obtained in the previous expedition. ECHO is a side scan sonar tow sled, an instrument that uses sound to create images of the sea floor and objects on it. ECHO is towed 50-100 meters above the sea floor and emits high-pitched "chirps" of sound diagonally through the water. The sound bounces back to ECHO from objects such as rocks, depressions or shipwrecks, creating a scanned picture of the sea floor as the vehicle progresses along. The images created look very much as though the surface was visually viewed from above, with lighting from very low and to the side. The sound bounces off only one side of any object, and generates long "shadows." The lengths and shapes of the shadows can reveal the shape and height of the objects.

SCUBA Operations

As this expedition is focused on deploying the ROV, there will be very limited scuba diving. The NOAA videographer will spend at least one day diving to capture images of LITTLE HERC and ARGUS. All SCUBA operations will be conducted from the SHENEHON and will meet standard NOAA dive protocols.