icebreakers Fennica and Nordica to serve as primary ice management vessels in the Chukchi Sea during the summer seasons. The primary purpose of Fennica would be to protect the drillship Noble Discoverer by steering large ice floes so that they don't endanger the drilling operation. The decision to charter the Finnish icebreakers to support Arctic offshore drilling has been widely criticized due potential environmental damage in case of oil spill. On 16 March 2012, some 52 Greenpeace activists from five different countries boarded Fennica and Nordica at Arctech Helsinki Shipyard to protest Shell's drilling operations in Alaska. In November 2012, Fennica and her sister ship became the first Finnish icebreakers to sail through the Northern Sea Route when the vessels returned to Finland for the 2012 icebreaking season. During the transit, the multipurpose icebreakers were escorted by Russian nuclear-powered icebreakers Rossiya and Vaygach. In 2013, Fennica and Nordica returned to Finland via the Northern Sea Route for the second time. In 2015, after the decision from Shell to stop drilling in Alaska, Fennica and Nordica returned to Europe via the Northwest Passage. This late-season eastbound unescorted transit was the first time the Finnish icebreakers have sailed through the Canadian Arctic Archipelago and was claimed to save both time and money. The ships arrived to Nuuk, Greenland, on 31 October 2015. Incidents On 2 July 2015, while underway to the Chukchi Sea to support Shell's drilling operations, Fennica struck an uncharted rock that created a long and about two inches () wide fracture in the Port No. 4 ballast tank. When the crew noticed that water level in the tank was rising, the icebreaker turned back and returned to Dutch Harbor for investigations. On 13 July, it was announced that Fennica would head to Vigor Industrial dry dock in Portland, Oregon, for repairs. This was not expected to delay Shell's plans to begin drilling in Northern Alaska as the capping stack, a critical piece of safety equipment carried by Fennica for shutting off the flow of fluids from an oil well in case of a blowout, would not be needed until later when the drill reaches depths where oil and gas are expected to be found. In Portland, Fennica was met by protesters who opposed Shell's plan to drill oil in the Arctic waters. Greenpeace activists hanging from the St. Johns Bridge as well as "kayaktivists" in the water tried to