( CNN ) Greenpeace activists have climbed aboard a Shell oil rig to protest the company 's plans to drill in the Arctic near Alaska . The six protesters used ropes and harnesses Monday to scale the huge platform in the Pacific Ocean , tweeting images of their daunting climb as they went . `` We made it ! We 're on Shell 's platform . And we 're not alone , '' wrote Aliyah Field , an American activist taking part in the protest . `` Everyone can help turn this into a platform for people power ! '' The rig , the Polar Pioneer , is on its way to the Arctic via Seattle . The environmental activists caught up with it about 750 miles northwest of Hawaii , Greenpeace said . They plan to occupy the underside of the rig 's main deck and say they have enough supplies to stay there for several days . Shell did n't immediately respond to CNN 's request for comment late Monday . But company spokeswoman Kelly Op De Weegh told Agence France-Presse that the boarding was illegal and jeopardized the safety of the activists and the crew . Greenpeace is furious over a decision last week by U.S. authorities to lift the suspensions on leases to drill for oil and gas in the Chukchi Sea , which lies between northern Alaska and Russia . Shell and several other oil companies bought exploration leases for the sea in 2008 . The U.S. government 's decision `` means that in 100 days , Shell could begin drilling in the Alaskan Arctic , '' Greenpeace said . Federal agencies still have to review and approve companies ' plans before exploratory drilling can start . Shell 's work in the Arctic has suffered some setbacks in the past , including a drilling barge that ran aground off southern Alaska on December 31 , 2012 . Greenpeace has repeatedly used the occupation of drilling-related vessels to bring attention to its cause . One group of its activists was detained for months by Russian authorities in 2013 . In the current episode , the activists pursued the Polar Pioneer , which Shell is leasing from Transocean , as it traveled thousands of miles aboard a transport vessel from Malaysia , Greenpeace said . Besides the American protester Field , the activists come from Australia , Austria , Germany , New Zealand and Sweden . The U.S. Coast Guard was n't immediately available for comment late Monday on the incident . CNN 's Dave Alsup contributed to this report .
Six protesters scale the Polar Pioneer , thousands of miles northwest of Hawaii . Greenpeace opposes Shell 's plans to drill for oil in the Arctic .