Dynamics of the Ocean Floor
HyBis - a modular underwater robot
HyBis is a multi-purpose robotic underwater vehicle (RUV), which is controlled by a fiber optical cable and is equipped with a sampling grab. HyBis was developed by the National Oceanography Centre in Southampton (NOCS) and Hydro-Lek Ltd and can dive up to a depth of 6000 metres. GEOMAR’s HyBis is the second instrument after the prototype, which is operated by NOCS. Both vehicles were frequently used on numerous research cruises and contributed for example to the investigation of the deepest known hydrothermal systems in the world in the Cayman Trough (Caribbean Sea) in approximately 5100 metres water depth.
The vehicle has a modular design. The main module consists of the steering unit represented by two propellers as well as the energy supply, the cameras, the light, the hydraulic systems and the telemetry. Depending on the sampling requirements, different modules can be mounted under the main module. The modules available at GEOMAR include a hydraulic two jaw grab, a manipulator arm with a retractable sampling container and a module to deploy ocean bottom seismometers (OBS) on the seafloor. In contrast to a conventional remotely operated vehicle (ROV), HyBis is not neutrally buoyant. Both the descent and the ascent of the HyBis, as well as the operating depth are controlled from the ship by the fiber optical cable. Therefore, HyBis can deploy and recover a net load up to 700 kilograms (sampling equipment / sampling material), which is several times the payload of an ROV. However, as a direct consequence of this configuration HyBis is not as maneuverable as an ROV.
So far, the GEOMAR HyBis was deployed offshore Taiwan, in the Mediterranean Sea and in the Gulf of California and has proven a valuable tool for groundtruthing in situ at the seafloor geophysical remote sensing results. Thus, and because of its capability to take video-guided rock and sediment samples without the need for dedicated technicians HyBis closes the gap between the complex and logistically demanding ROV operations and “blind” sediment sampling techniques, such as dredging or gravity coring.