Remotely Operated Underwater Vehicles, or ROVs, are essential tools for both the geologists and the biologists on board. They are controlled by specially trained pilots on the ship, who use the robotic arms of the vehicle to take samples such as fresh sulfide chimneys from a black smoker, microbial mats or fauna living on the seafloor. This approach has a significant advantage over dredging and trawling, because the ROV allows for selective sampling and registers the exact location where the samples are taken. Sensors measuring for example the temperature at the seafloor and high-definition cameras filming the hidden underwater world are also added to the ROV, to get as much information from one dive as possible.
ROV Aglantha (image from imr.no)
ROV leg 1: Aglantha
The ROV used during leg 1 (Aglantha) is a small ROV equipped with camera equipment that will mainly be used for exploration purposes, as well as dropping the lander on the seafloor. More information (in Norwegian only) can be found on this website from the Institute of Marine Research.
ROV leg 2: Argus Bathysaurus
EDIT: Actually, we got an even bigger ROV on board during the second leg, the Argus Mariner XXL…
A larger ROV (Argus Bathysaurus) will be loaded onto the ship in Tromsø, to be used for sampling of rocks, fluids and sediments during the second leg of the cruise. Depending on the requirements for each dive, the ROV will be equipped with tools such as a modified chainsaw for the cutting of rock samples, push cores for the collection of small sediment cores, gas-tight titanium bottles and syringes for the collection of vent fluids and gasses or a biosyringe for the collection of microbial mats and fauna samples. In addition, the ROV is capable of deploying the microbial and geochemical incubators at the seafloor for long-term experiments.
Read more about the Bathysaurus: Argus Bathysaurus 3000m ROV TMS_Spec sheet
Watch this video (in Norwegian only) and follow Rolf Birger Pedersens explanation on the ROV.
Curious to see a chainsaw in action at 3000 meters water depth? Check this video that was recorded during a cruise together with the Norwegian Petroleum Directorate in 2013, using the Swire Seabed ROV and filmed with the Argus Bathysaurus (skip to 04:30 to see the chainsaw in action).