It was the first step in a potentially serious accident -- but so far as we know, no worse than that.
Tonight (Saturday) the U.S. Coast Guard says the Shell Oil Company Drilling Rig "Noble Discoverer" has been successfully re-anchored near Hog Island in Unalaska Bay.
That after the 14,000-ton-vessel started an uncontrolled drift late in the afternoon, dragging its anchor in 35-mile-an-hour winds.
The crew -- and a Shell Oil tugboat -- apparently managed to stop the drift just before the oil platform would have run "soft aground" on the Unalaska shore.
U.S. Coast Guard Spokesperson Sara Francis says no one was injured in the incident, and no pollution resulted from it.
The oil rig was anchored in Unalaska Bay while en route to the Arctic Ocean -- off the coast of Northwest Alaska-- for planned exploratory drilling later this summer. The "Noble Discoverer" and its sister drilling platform "The Kulluk" are weeks behind schedule after unusually heavy Bering Sea ice blocked their path in early July.
It's still not clear what this incident will do to Shell's plans to drill exploratory wells in the Chukchi and Beaufort Seas in August and September. The company had hoped to start drilling last year. But its plans were blocked due to the environmental fallout from a huge BP oil spill in the Gulf of Mexico in early 2010.
It's not clear why the "Noble Discoverer" lost its mooring at 5:18 in the evening, but the Coast Guard says the soft bottom of Unalaska Bay does make it difficult for an anchor to get a good "bite".
Meanwhile, environmental groups are reacting harshly to the incident. Lois Epstein, of "The Wilderness Society" says she's very concerned that the rig suffered an incident like this in the relatively benign conditions of Unalaska Bay. Epstein says that winds and sea conditions in the Arctic Ocean can get much harsher than anything the vessel has experienced so far in its journey.
Shell Oil has now dispatched a dive team to Unalaska. By Monday, they're expected to enter the water and inspect the "Noble Discoverer" for damage.
The hope is that it did not scrape bottom.
Initial signs are encouraging. The rig's crew says it felt no vibration when the vessel drifted to within 175 yards of shore. They also saw no evidence that its 100-foot-tall derrick had swayed.
At this hour, it's still not clear what the incident will do to Shell's plans for exploratory drilling in the Arctic Ocean this summer.
As of 9 P.M. Saturday, the Coast Guard said winds in Unalaska were still blowing at 35-miles-an-hour and seas were at 4 feet.
Those winds were not forecast to start dying down until sometime past midnight.