Navy ships from Pearl Harbor and San Diego pitched and rolled as they cut through 6- to 9-foot seas off Kauai last week, testing their ability to hunt submarines and fend off missile attacks from enemy jets.

Koa Kai, a big Navy readiness exercise held semiannually in Hawaii, got even bigger as at least a dozen ships — including a Canadian oiler — gathered for the training.

There was the familiarity of interoperability that’s been there for decades, but in 2014 the threat and economics of war are changing, and so is Koa Kai.

Rather than sending an aircraft carrier, a costly proposition in an era of military budget cuts, the Navy sent the command staff of the USS John C. Stennis from Washington state to simulate a strike group while the flattop is in maintenance.

And among the helicopters landing on ships and being sent aloft to check out approaching small boats were small Army OH-58D Kiowa Warrior scouts with mast-mounted optics that can look out several miles.

As a benefit to that service cross-pollination, when a crew member on the cruiser USS Port Royal experienced heart problems Wednesday — real, not simulated — an Army medevac Black Hawk helicopter taking part in the exercise picked him up from another ship and whisked him to Tripler Army Medical Center.

Army Black Hawks, Kiowas, big Chinooks and Marine Corps Cobras were on the flight line at Kauai’s Pacific Missile Range Facility for the exercise, and Marine F/A-18 and Hawaii Air National Guard F-22 jets zoomed overhead.

Navy P-3 Orion sub-hunting aircraft from Kaneohe Bay and a new P-8A Poseidon jet out of Washington state also were involved.

"There’s a lot of moving parts here," said Navy Capt. Chris Bushnell, commander of Destroyer Squadron 31 at Pearl Harbor. "So this is not your father’s Koa Kai. We’ve raised the bar here."

The weeklong exercise, the biggest ever Koa Kai (Hawaiian for "sea warrior"), just wrapped up.

The Army in Hawaii has been training increasingly to land its Black Hawk and Kiowa helicopters on Navy destroyers and cruisers, and in a Pacific rebalance that favors a light footprint and ability to arrive and leave in a hurry, the service has been accused of wanting to become more like the Marine Corps to retain relevance and budget share.

Rear Adm. Rick Williams, the commander of Naval Surface Group Middle Pacific and Navy Region Hawaii, takes a different view of the joint training.

"We (all the service branches) are all finding ways to support each other in this austere budget environment," Williams said. "We’ve got to combine (training) elements, in my opinion."

The Army, seen as the equipment-heavy force that sets up camp for the long haul in a foreign country (something the United States would rather not do now), admits it needs to be more "expeditionary" — in other words, be more mobile, like the Marines.

John Pike, director of Virginia-based think tank GlobalSecurity.org, said all the services, not just the Army, are worried about their budgets.

"I think they are all very insecure," he said.

He also thinks there’s plenty of room for Army helicopters on Navy ships.

"There are never enough helicopters when you’ve got a disaster," Pike said.

And the Pacific is very disaster-prone.

"Look at all those Nimitz carriers," Pike said. "That’s 4.5 acres of perfectly good sovereign American territory that’s got (few) helicopters on it to speak of — and that’s going to waste (in a disaster-relief situation)."

In the rebalance to the Pacific, meanwhile, the semiannual Koa Kai is taking on increased importance.

Pearl Harbor-based ships started conducting intermediate and advanced training off Hawaii and in the western Pacific in 2009 to save time and money by reducing transits to San Diego for the deployment practice.

That morphed into Koa Kai in 2010, Navy Region Hawaii said.

Williams, the Naval Surface Group Middle Pacific commander, sees even more potential for the vast sea and air space of the Pacific Missile Range Facility where Koa Kai just wrapped up.

PMRF "has one of the biggest areas of operation to train in where you can put submarines, airplanes and ships in a fairly unconstrained operation," he said.

"And as you see the changing threat environment where there are more advanced missiles and advanced ballistic missiles and more advanced submarine capabilities, you need an area where you can train in to do all of those simultaneously," Williams added. PMRF is that place, he said.

Seven Pearl Harbor surface ships participated in Koa Kai, including the cruisers Port Royal, Lake Erie and Chosin, and destroyers Michael Murphy, Halsey, Chung-Hoon and O’Kane, as well as several unnamed submarines.

The cruisers Cape St. George and Lake Champlain came from San Diego, and the Canadian replenishment ship HMCS Protecteur also participated.

On Wednesday, the destroyer Halsey was operating 25 miles northwest of Kauai in 6- to 9-foot seas as the Michael Murphy, Chosin and Protecteur could be made out 5 to 10 miles away.

In the scenario, the United States supported country "Green" as country "Red" tried to press its will on "Green."

Halsey commander Cmdr. Gary Cave said eight "enemy" planes were inbound, and four defenders were in the air.

"We’ve got to figure out how to manage that," Cave said.

Cave was standing by to see if his ship possibly would be assigned as an air control unit for the defending jets, or an air defense unit with the ability to simulate the launch of surface-to-air missiles.

"The number of things that we’re getting out of this — while we do a lot of simulation, you can’t simulate this, the sea spray in your face, being 200 feet across from a Canadian oiler getting gas, looking out and seeing nine other ships around," said Bushnell, the destroyer squadron commander.

Onboard the Halsey amid the Navy blue was Army Capt. Edward Richards, 26, a liaison for the 25th Combat Aviation Brigade out of Wheeler Army Airfield.

"It’s a humbling experience" being out in the middle of the ocean on a rocking vessel, Richards said.

Patrick Rader, a contracted helicopter pilot for the Croman Corp. out of PMRF who has made hundreds of Navy ship landings in a big Sikorsky S-61N, said landing on a rolling ship initially can be a challenge.

"The boat kind of becomes your horizon," he said. "Psychologically, you are looking at the boat. The boat’s all over the place so you end up trying to chase the boat. You just have to follow the horizon and keep your aircraft stable in relation to the horizon and then come onto the boat."

The aviation brigade starting practicing landing on Pearl Harbor ships last July. It hadn’t done so for more than a decade during the war years.

Chief Warrant Officer 3 James Mason, a 32-year-old Kiowa pilot with three tours to Afghanistan, said he made his first ship landing a few weeks ago and was making several landings a day on ships during Koa Kai.

"It’s not too bad," he said. "We had limits as to when we could land and things of that nature based on the sea state."

Lt. Col. George Ferido, commander of the 2nd Squadron, 6th Cavalry Kiowas, said landing on a ship is "interesting (and) very intense."

There are equipment differences between the Army’s Sikorsky UH-60 Black Hawk and the Navy’s Sikorsky SH-60 Seahawk, including a tail wheel farther back on the Black Hawk, making for a bigger footprint.

"I know the SH-60 folds up like a nice present (for ship storage) whereas our helicopters don’t fold up completely. It’s a lesson learned," Ferido said. "I think we’re learning a lot of lessons from just Koa Kai and our previous training event that we’ll take back and look at our training plans to enhance them and help the Navy and help the Marines to see how we can contribute to the fight."