An interesting tanker was seen on Saturday as she left the Clyde following a discharge of crude oil from the North Sea's Troll Field. MASTERA, owned by the Finnish oil company Neste, is described as a 'double-acting tanker' and is one of a pair of ships designed by Kvaerner-Masa Yards and built in Japan by Sumitomo Heavy Industries at their Yokosuka shipyard. MASTERA, and her sister TEMPERA, are designed to be able to operate in an ahead direction in open water, or astern in pack ice, using her special hull design to break through the ice. Propulsion is by a single azipod unit with a single, fixed pitch, propeller. MASTERA is of 106,208 tonnes deadweight, and has an overall length of 252 metres.