The Coast Guard icebreaker Healy is on its way to a four-month summer mission in the increasingly important and busy Arctic Ocean — after a Honolulu detour for some training and rest and relaxation.

The 420-foot ship, which has the ability to carve through up to 10 feet of ice, left Seattle earlier this month and is tied up at Aloha Tower with public tours available from noon to 4 p.m. Saturday at Pier 11, officials said. The ship will depart Tuesday.

The Healy and its crew of about 87 are using the visit to conduct helicopter landing recertification with the Coast Guard air station at Barbers Point — and absorb some warmth before heading north, said Healy operations officer Cmdr. Bill Woityra.

“The crew is very excited about coming here and spending a few days before we spend the next four months up in the Arctic,” Woityra said. “As soon as we leave here, we go to Seward, Alaska, and we’ll pick up the scientists at the end of June and we’ll be up in the Arctic the first week of July.”

Altogether, the ship will be gone about 4-1/2 months, he said. Dozens of scientists will be on board.

One of three missions the Healy will conduct is in support of the State Department and White House Office Office of Science and Technology to perform multibeam sonar mapping and bottom dredging in the Bering Sea and Arctic Ocean to help demarcate the Extended Continental Shelf.

The State Department said the Extended Continental Shelf is that portion of the shelf beyond 200 nautical miles from shore. The U.S. ECS is “an important maritime zone that holds many resources and vital habitats for marine life,” the department said.

Arctic ice is melting at a fast rate, creating greater opportunities for shipping, and Coast Guard Commandant Adm. Paul Zukunft noted this week at a forum in Washington, D.C., that the region has seen a 300 percent increase in human activity.

“Conservative estimates are that about 13 percent of the world’s oil and about a third of the world’s natural gas and about a trillion dollars’ worth of minerals reside on the seafloor up in the Arctic region,” Zukunft said.

The operational U.S. polar icebreaking fleet consists of one heavy icebreaker, the Coast Guard’s Polar Star, and the medium icebreaker Healy. With multiple countries staking claims in the Arctic, concerns have been raised that the United States has fallen behind in what Foreign Policy magazine calls the “race for influence.”

Russia, by comparison, has 41 icebreakers. The biggest and newest icebreaker in the world, the Arktika at 568 feet and powered by two nuclear reactors, was unveiled Thursday and will be used by Russia to transport liquefied natural gas from the Arctic.

In 2013 the Department of Homeland Security said the Coast Guard “will need to expand its icebreaking capacity, potentially requiring a fleet of up to six icebreakers (3 heavy, 3 medium) to adequately meet mission demands in the high latitudes.”

One new icebreaker at a cost of about $1 billion is planned to be built beginning in fiscal year 2020, according to the Congressional Research Service.

Zukunft said the oil and gas in the Arctic can be looked at as a strategic reserve for the United States. “You can also look at the fact that we’ve done extensive sea mapping beyond our traditional 200-mile economic exclusive zone,” he said. “But we’ve seen other nations up there doing scientific research and establishing a pattern of operating in this very same area as well.”

The Healy’s missions also will focus on the biology, chemistry, ecology and physics of the Arctic Ocean and its ecosystems. The 16,000-ton icebreaker cuts through ice while the Polar Star rides up and over it, crushing it as it goes, said Ensign Brian Hagerty, a deck watch officer.

Last summer the Healy became the first U.S. vessel to reach the North Pole by itself. Hagerty said the icebreaker can cut through 4-1/2 feet of ice continuously and has broken up to 10 feet by “backing and ramming.”

“It’s interesting because when you are up on the ice, you always hear it rubbing against the ship as you are transiting through it — which for us is no big deal since we’re constructed to do exactly that, break the ice,” Hagerty said.