The launch of an operation this week to pump out dozens of tons of fuel from the wreck of a cruise ship that sank off Santorini in April 2007 immediately hit a hurdle as the fuel in the tanks of the rusting vessel has solidified. «It has the consistency of toothpaste,» said Matthaios Saliveros of the coast guard team overseeing the operation. A hole was cut into the side of the Sea Diamond but suction pipes were unable to remove the substance from the tanks, Saliveros said. The aim is to remove the majority of an estimated 120 tons of fuel from the tanks by mid-June. Some 300 tons of leaked fuel had been collected from the sea in the months after the sinking. Merchant Marine Minister Anastassis Papaligouras, who visited the island yesterday to oversee the operation, noted that scientists were studying the area to determine whether it is advisable, and feasible, to lift the wreck off the seabed.