ANCHORAGE — A giant floating drill rig that ran aground a week ago on a remote Alaska island arrived as planned Monday in the shelter of a Kodiak Island bay after being towed about 45 miles through swells as high as 15 feet, officials said.

The Royal Dutch Shell PLC vessel was lifted off rocks late Sunday and towed away from the southeast side of Sitkalidak Island, where it sat exposed to the full-on fury of Gulf of Alaska winter storms since grounding near the beach there on New Year's Eve.

The Kulluk -- a circular vessel with a diameter as long as nearly three basketball courts -- was towed for about 12 hours to the protected waters in Kiliuda Bay, where it will undergo further inspection, including an underwater look at its hull.

"We could not be more impressed with the caliber of the response and recovery crews who were safe and meticulous in their effort to move the Kulluk offshore," Shell Alaska spokesman Curtis Smith said by email.

The vessel will remain in the bay 43 miles southwest of the city of Kodiak until inspectors review its condition and the Coast Guard clears it to travel. Shell incident commander Sean Churchfield said there's no timetable for departure.

"Until we have that damage assessment, we'll not be able to develop those plans," Churchfield said at a news conference Monday morning.

The massive effort to move and salvage the ship involves more than 730 people, according to the Unified Command, which includes the Coast Guard, Shell and contractors involved in the tow and salvage operation. Eleven people are aboard the ship -- a salvage crew of 10 people headed by Netherlands-based Smit International and one Shell representative.

Shell earlier reported superficial damage above the deck and seawater that entered through open hatches. Water has knocked out regular and emergency generators, but portable generators were put on board last week.

The Shell-owned Kulluk is 266 feet in diameter with a derrick in its middle and a funnel-shaped, reinforced steel hull that allows it to operate in ice. Its derrick rises 160 feet. It drilled last year in the Beaufort Sea and was headed to Seattle for upgrades and maintenance when it ran into trouble.

Environmentalists have called for a halt to Arctic offshore drilling as a result of a series of problems with Shell's closely watched 2012 effort, including a criminal investigation over issues with safety and pollution control equipment on its other drill ship, the Shell-contracted Noble Discoverer.

On Monday, Shell Oil Co. president Marvin Odum said in a written statement about the Kulluk that the company does extensive preparation to ensure such incidents don't occur and is sorry about the grounding.

"At this stage, it's too early to gauge any impact on our ongoing exploration plans, but with the Kulluk now safely recovered, we'll carry out a detailed assessment of the vessel to understand what those impacts might be," Odum said.

Its towing vessel, the 360-foot anchor handler Aiviq, on Dec. 27 lost its line to the Kulluk in heavy seas and while it reconnected to an emergency tow line, hours later it lost power to all four of its engines, possibly due to contaminated fuel. The cause of the multiple engine failures is under investigation by both Shell and the Coast Guard.

Four reattached lines between the Aiviq or other vessels also broke in stormy weather. The Aiviq on New Year's Eve again broke its line, leaving the Kulluk attached to the tugboat Alert.

Coast Guard Capt. Paul Mehler, the federal on-scene coordinator, said Monday the Alert also experienced a mechanical problem the night the Kulluk went aground.

But an official with Crowley Marine Services, which owns the Alert, said Monday evening that the Alert never lost power, though in the storm, it also wasn't able to hold the Kulluk in place off shore.

The Alert's engines were running at maximum power, setting off automatic engine shut-down alarms. The tug captain was operating manually and the engines didn't lose power or malfunction, said Charlie Nalen, vice president of operations for Crowley in Valdez, where the Alert is normally based for use as an oil tanker escort.

"You've got serious weather conditions and hurricane-force winds and seas, and they are being drifted back toward the beach, full throttle ahead on both engines," Nalen said. "The computer started flashing what's called summary shut-down alarms."

An assessment of what happened with the Alert will be part of the Coast Guard investigation, Mehler said earlier in the day.

"The understanding the night of the response was that when she was taking maximum power, there was an engine problem," Mehler said. "They did recover that within 30 minutes. The details of that, I couldn't answer yet."

Struggling against the storm, the Alert's crew was directed to let the Kulluk's line go. It grounded minutes later.

Inspections after the grounding determined that the Kulluk could be towed, and the Aiviq on Sunday reattached a tow line. Tension was added to test the line Sunday night and increased as high tide approached, Churchfield said.

He was not on scene but did not hear of complications.

"The Kulluk came off reasonably easy, would be my assessment," he said.

Mehler said he was in the command center when salvors reported the Kulluk had come off the rocks.

"I won't say that I saw anyone high-fiving," Mehler said. "I'll say there was certainly a sense of relief, but recognizing now we have a lot more work to do."

Likewise, the tow "has gone pretty much according to plan," Churchfield said.

Inspections will involve an underwater look at the hull with divers or remotely operated underwater vehicles or divers or both, he said. A dive boat platform should be at the scene Tuesday or Wednesday, Churchfield told residents of Old Harbor in a teleconference.

Around 9 a.m. Monday, as the Aiviq and Kulluk approached safe harbor in Kiliuda Bay, a second tow line was secured to the Alert, which helped with steering and braking, according to Ignacio Gonzalez, a spokesman for the command team who normally works for Shell in Houston.

At 12:15 p.m. Monday, the Kulluk was anchored to the bottom of the bay. The Aiviq was nearby but no longer attached to the Kulluk, the command group said.

The Alert and two other tugs, the Lauren Foss and the Corbin Foss, remained tethered to it as of mid-afternoon, according to the command team. The Coast Guard cutter Alex Haley, two oil spill response vessels, and two other tugs were also in the area.

A tug trailing the drill vessel used infrared equipment to watch for oil sheens and reported no petroleum discharge.

At this point, the response team does not plan to remove the fuel, because of the risk of a spill.

The response effort includes crews on the vessels, a command group in Kodiak and the main command team based at the Anchorage Marriott Downtown.

Before the grounding, Shell had spent more than $4.5 billion on leases, vessels and equipment for its first drilling season offshore the Alaska Arctic in two decades.

Daily News reporter Lisa Demer contributed to this story.