Helicopters and aircraft buzzed around the grounded Royal Dutch Shell drill rig Kulluk on Friday like bees around a hive, but there were few significant developments as authorities continued to work on a possible salvage plan for the 266-foot offshore drilling unit.

It was the fourth full day that the Kulluk had been stranded on the shore of Sitkalidak Island, near the larger Kodiak Island in the Gulf of Alaska. The Kulluk ran aground on New Year's eve after a multi-day effort to tow it further from landfall in high, stormy seas.

After salvage crews boarded the vessel on Wednesday and Thursday, looking for any damage and in particular any breaches in the drill rig's reinforced steel hull, the Coast Guard reported that salvage crews had again been delivered to the Kulluk on Friday. The Coast Guard said that the team is "providing critical information in support of development of a final recovery plan."

The team reported on Thursday that the hull of the Kulluk appeared to remain intact, keeping the potentially 150,000 gallons of fuel the rig carries from leaking into nearby waters. Oil containment booms were delivered to the community of Old Harbor, the village nearest to the Kulluk, as a precaution.

Additionally, vessels continued to arrive in the area to assist with whatever salvage effort moves ahead -- whenever that might be.

"On-water, 14 vessels have been mobilized to support the response and recovery," said a statement from the Unified Command -- a cooperative agency consisting of the Coast Guard, the Alaska Department of Environmental Conservation, Shell and Noble Corporation, which owns the Kulluk -- in charge of the Kulluk response effort. "Three of these vessels are on location, with the other 11 either en route or on standby at nearby ports and harbors."

That included the Shell tow vessels Nanuq and Aiviq, which had been stationed in Kodiak Harbor until Friday afternoon, when they pulled away. Where they were going -- or whether they'd just been anchored elsewhere -- was unknown. More vessels were also reportedly on the way from Seattle and expected to arrive by this weekend.

In addition to staging more equipment and delivering the salvage team, another helicopter flight also carried biologists, examining the wildlife in the region for any possible environmental impacts.

There were a couple of bright spots in the midst of the crisis, the first being the news that the Kulluk's fuel tanks -- located on one side of the rig -- were facing out to sea and not bumping against the rocky bottom where shore meets ocean. And the weather for Friday was calmer and expected to remain that way through Sunday night, with moderate winds and seas wobbling around 10 feet.

There were no indications that the situation would be resolved in the near future, though things may move quickly once a final plan is put in place. For now, the Kulluk continues to sway in the shallow waters on the shore of Sitkalidak Island.

Contact Ben Anderson at ben(at)alaskadispatch.com