On Thursday, the first vessel in Royal Dutch Shell's Arctic drilling fleet, the Arctic Challenger, has started its journey from Washington State to Alaska.

For now, it is not known when it would reach. The Arctic Challenger had left Bellingham, north of Seattle, and has been heading towards Dutch Harbour, off mainland Alaska. The Arctic Challenger is one of the vessels that will be taken to drilling rigs. The search for fossils fuels will start by next month in the Chukchi and Beaufort Seas, considered among the world's most ecologically sensitive areas.

As per environmentalists, an oil spill in the area, which is majorly covered with sea ice and vulnerable to rapid changes in weather conditions, could prove taxing to the ecosystem and will be very difficult to clean the area.

Shell's decision to temporarily house a drilling rig in Seattle had led to many protests. Protestors have tried to block access to the vessel. In fact, the activists said that they will form a task force, so that the rig cannot leave the city's Elliot Bay.

The company has not shared details as to when it is planning to depart the rig, the Polar Pioneer. But activists think that the rig would depart by this week. But a shipping source said that the rig would leave by the end of June.

Shell is waiting to get federal permits. The oil giant said that it can safely resume drilling and will also clean up to 90 to 95% of any oil spilled. On Thursday, a federal appeals court has upheld Shell's oil spill response plans.