However, after a more than three-hour delay, the rig is now on the move, and activists say kayakers up the channel are prepared for more resistance.
Meanwhile, praise for the bravery of the 'kayaktivists' has come from all corners. "Today, the Puget Sound is the scene of some serious climate heroics," tweeted David Turnbull, campaigns director at Oil Change International.
350.org founder Bill McKibben wrote, " My favorite new word of 2015 is 'hacktivist,' and this a.m., they're giving Shell fits in Seattle's harbor."
Updates on the rig can be found on Twitter under the hashtag #SHellNo.
Earlier
In canoes and kayaks, anti-drilling activists early Monday faced down Shell's 40,000-ton drilling rig, the Polar Pioneer, as it attempted to set sail from Seattle's Puget Sound to Arctic waters.
At least ten of the "kayaktivists," including Seattle City Councilmember Mike O'Brien, were detained by the U.S. Coast Guard for alleging violating a previous injunction by overstepping a 500-yard restricted "safety" zone around the behemoth rig.
An estimated 40 to 50 supporting kayakers lined up in the waters behind the initial blockade while the group floated an enormous banner which read: "SHell No!"
Watch:
According to reporting on the scene by Yes! Magazine editor-in-chief Sarah van Gelder, after the first wave of arrests, more kayakers continued to blockade the rig as it made its way through the Sound.
The demonstrators hope to stall the rig long enough to thwart Shell's sensitive drilling timeline. They say they are putting their bodies on the line for the sake of the pristine Arctic ecosystem and the future of the planet—both of which are now at great risk due to the fossil fuel industry's insistence on extracting more oil from increasingly remote sources, such as the Arctic seabed or Canadian tar sands.
They note that this policy has enjoyed continued support from President Barack Obama's administration despite his repeated statements on the urgency of the climate crisis.
"Every minute that brave protesters can delay Shell's Arctic drilling plans is another chance for President Obama to reconsider his disastrous approval of oil drilling in Alaska," Greenpeace U.S. executive director Annie Leonard said in a statement. "The President's decision on Arctic drilling will be a dealbreaker for his climate legacy, but it's not too late for him to stop this catastrophe before it starts."
Paloma Henriques, one of the kayaktivists in the blockade, added: "I'm just one voice out here, but I know I'm not alone. I believe that confronting Shell will encourage more people to take a strong stand against them and other companies who are seeking to destroy this planet for profit."
In addition to blocking Shell, Henriques said that the group is sending "a message to President Obama that it's not too late to stop Shell from destroying the Arctic."
Over 300,000 people have signed a petition calling on Obama to abort the Arctic drilling plan.
Updates on the blockade are being shared online under the hashtag #SHellNo as well as on Greenpeace's live blog.