Autosub3 is an autonomous underwater vehicle (AUV) which can access locations such as underneath icebergs and glaciers that are otherwise impossible to survey using conventional vehicles. For each mission Autosub3 is programmed with a survey. It will then follow this survey using its own navigation system. However, the vehicle can also think for itself in order to avoid obstacles and also to return to a safe position if it detects any major problems. Its main instruments are a bathymetric sonar and a pair of CTD units which give the water's salinity, temperature and 'murkiness' - all vital clues to where the water has come from and its composition.
BRIDGET is a towed chemical and water sampling and measurement vehicle. As well as the regular salinity, temperature and 'murkiness' measurements, BRIDGET can also be fitted with methane, iron, manganese and other chemical sensors. These give scientists clues as to the presence and location of a hydrothermal site – an underwater hot spring – characterised by a plume of chemicals rising several hundred metres above the sea floor. By towing BRIDGET through the plume in a criss-cross pattern the extent and location of the spring can be determined. The site can then be investigated in more detail using other vehicles such as the ISIS ROV or SHRIMP.
Isis is a remotely operated vehicle capable of descending to 6500m below the surface of the ocean. An operator in the control van aboard the mother ship can guide the vehicle to precise locations by sending commands to the vehicle's thrusters. Once there the operator can use the ROV's manipulators like arms and hands to do scientific tasks such as taking samples and deploying instruments. The operator can view the sea floor through up to 8 separate cameras mounted on the vehicle. ISIS also has sophisticated sonar systems to make high resolution bathymetry maps of the seafloor as well as chemical sensors and a 'slurp' gun to take mid water biological samples.
SHRIMP – Sea floor High Resolution Imaging Platform – is an underwater video and photographic vehicle capable of taking pictures at depths as deep as 6000m. Equipped with an array of video cameras, lights, stills camera and flash it gives scientists a real time view of the sea floor thanks to the use of fibre-optic telemetry.
SHRIMP is very robustly made with a heavy stainless steel frame – approximately 1T in weight - built to withstand regularly being crashed into the rocks and boulders of the sea floor.
TOBI – Towed Ocean Bottom Instrument – is a deep towed sidescan sonar vehicle capable of giving amazing sonar images of the deep ocean. Pulses of sound are transmitted sideways from the vehicle and the echoes received build up into a high resolution 6km wide image of the sea floor – TOBI can resolve objects of approximately the size of a snooker table. In order to preserve the quality and width of the images, TOBI is flown close to the seafloor by an operator on the mother ship. By adjusting the ship's speed and the amount of cable between the ship and the vehicle, it can be kept at the optimum height of 300-500m above the sea floor – in rough terrain an operator's job is very demanding!