The San Diego-based littoral combat ship USS Fort Worth, a high-profile symbol of the Navy’s strategic shift to the Pacific, has been busy en route to Singapore for a 16-month assignment — the second such experiment of rotational duty to the Southeast Asian nation.

On the way to Hawaii, the Fort Worth trained with its 31-foot MQ-8B Fire Scout unmanned helicopter.

About 10 miles off the Wai­anae coast on Tuesday, Army Black Hawk medevac helicopters practiced landing on the ship’s pitching and rolling deck. Marine Corps helicopter landings also were scheduled.

But the real test of the still-evolving shallow-water ship will come in the months ahead as the Navy repeats the Singapore deployment with a type of vessel that has had its share of critics.

On its 2013 deployment to Singapore, the USS Freedom, LCS-1, was underway only 35 percent of the time due to mechanical failures, the U.S. Government Accountability Office reported in July. The vulnerability of the relatively lightly armored aluminum and steel design is another concern.

Cmdr. Ken Bridgewater, the Fort Worth’s commanding officer, said more than 400 improvements were incorporated into his ship, the third of its kind, LCS-3.

It’s also sporting a racier $1.4 million paint job, a geometric camouflage, compared with sister ship Freedom’s World War II-era design.

The 387-foot Fort Worth underwent a "total ship survivability" test in September off the Cali­for­nia coast in which it faced a barrage of simulated weapons, Bridgewater said.

The simulation disabled radars and other systems, leaving the Fort Worth temporarily dead in the water, he said. The crew’s task: getting the ship underway again.

Fog machines replicated smoke from fires. The simulation also included flooding and structural damage, crew members said.

The final report is not out yet, "but all indications are that (the ship’s response) was very successful, and we were able to demonstrate that the crew, based on current training levels, would be able to combat a majority of any type of damage that we took," Bridgewater said.

The littoral combat ship was intended to be a comparatively low-cost and speedy surface warship that could operate in the shallow waters close to shore, where a majority of shipping occurs.

But the effort has been slowed due to cost overruns and vulnerability concerns.

Defense Secretary Chuck Hagel cut back the program to 32 from 52 ships in February and asked for improvements or an alternative design. A revised design for the last 20 ships is expected to be picked soon by the Defense Department.

"We need small surface combatants," Adm. Jona-than Greenert, chief of naval operations, told the Senate Armed Services Committee in March. "We need 52."

But he said the ships need "better survivability," that is, the ability to defend themselves but also take a hit and keep operating. Greenert also noted that "this ship has the ability to grow," adding, "It has speed, it has volume and it has capacity."

Some Navy officials have said the littoral combat ship’s 2013 deployment problems are typical for any new class of ship. Four of the ships are expected to use Singapore as a maintenance and logistics hub on rotational deployments in coming years.

Four crews are scheduled to rotate onto the Fort Worth over its 16-month stay, officials said.

Two types of the LCS are being built: the Freedom variant, with a single steel hull and aluminum superstructure, and the 419-foot Independence class, an aluminum trimaran, or catamaran with three hulls. Fort Worth’s design is the former.

The Fort Worth has a draft of about 14 feet and can make speeds of more than 46 mph, according to the Navy. By comparison, a destroyer has a draft of 31 feet.

"We’re designed to operate in close-in, congested waters," said Lt. Mike Chesnut, the Fort Worth’s operations officer.

Chesnut said the ships are designed to have a small crew (just under 100 for the Fort Worth) and with equipment that can be swapped out for different missions.

The Fort Worth is equipped with a surface warfare mission package with two 30-mm guns, two 36-foot boats and two eight-member boarding teams, officials said.

Off the Waianae coast on Tuesday, two Army Black Hawks rotated pilots who practiced landing briefly on the Fort Worth’s relatively large flight deck. It’s a skill the Army is increasingly practicing in Hawaii as the service, which specializes in land warfare,seeks to become more versatile.

"All it does is increase our flexibility so we can be that true joint force partner out there," Bridgewater said of the cross-service practice.

That could be important for humanitarian assistance missions in the future, he said.

Hospital Corpsman Chief Sloane Sall, 36, the Fort Worth’s medical provider, said it’s kind of "surreal" to see the ship in action because some of the crew commissioned the ship in late 2012.

"So to see all of these evolutions and finally get to go on deployment — which we have been talking about for the last two years — feels good, like we’re completing our mission," said Sall, who is from Mount Vernon, Ohio.

Other changes are coming for the ships. Among them, the Navy is looking at arming the LCS with long-range surface-to-surface missiles.

Bridgewater said the Fort Worth can get into ports that are too shallow for some other Navy ships, and the smaller size of the LCS makes it less intimidating to regional partner navies.

The ship will head to Guam and then Singapore and the South China Sea for operations, he said.

The Fort Worth is expected to participate in the CARAT (Cooperation Afloat Readiness and Training) series of exercises held with Bangladesh, Brunei, Cambodia, Indonesia, Malaysia, Philippines, Singapore, Thailand and Timor Leste.