The Marine Corps' top combat gear developer defended the service's next-generation amphibious vehicle on the Capitol Hill Wednesday, telling lawmakers saying it would be preserved above all else — even as looming budget cuts another likely round of sequestration threatens efforts to modernize its ground vehicle fleet.

The Amphibious Combat Vehicle 1.1 is critical to the service's ability to execute its traditional mission in the years ahead and is now the service's "number one No. 1 priority" after amphibious modernization took a back seat during the wars in Iraq and Afghanistan, Lt. Gen. Kenneth J. Glueck Jr., the commanding general at Marine Corps Combat Development Command's commanding general, told the members of the Senate Subcommittee on Seapower.

"To be the Marine Corps you want and our nation needs, we need to do some vehicle modernization," Glueck said.

The demand for expeditionary missions requiring amphibious capabilities will only increase in the years to come, he added. The ACV 1.1 will be at the heart of that mission, although some the vehicle does have detractors who question the vehicle's its inability to quickly cross swim long distances.

Glueck was repeatedly questioned by lawmakers about how a new round of service's broad contingency budget plans if across-the-board spending cuts, which could hit again in October, would affect the Marine Corps' efforts to modernize its ground fleet.

He responded by stating saying there was no current Marine-specific plan because any plan would be dependent on the broader national defense strategy developed under sequestration. That strategy would set forth a joint force plan that the Marine Corps would then work to fit.

And while all of the services could face another round of tough budget cuts, That hard reality all the services face is that sequestration would mean painful cuts. But, Glueck and Thomas P. Dee, the deputy assistant secretary of the Navy for expeditionary programs and logistics management, expressed concern the Marine Corps would be hit disproportionately hard, despite its expenditures accounting for only six 6 percent of the nation's overall defense budget.

When asked by Sen. Mazie Hirono, (D-Hawaii,) how the service will prioritize vehicle modernization under sequestration as a result, Glueck reemphasized that the ACV 1.1 program will be preserved no matter what.

The service will "take cuts from other programs to meet the defense strategy" before diverting resources from the procurement of the ACV 1.1, which is first in a line of next-generation amphibious vehicles that could eventually incorporate high-water speed.

Multiple companies are now vying for the final ACV 1.1 contract with prototypes being tested in Nevada and California. But, it will likely be an eight-wheeled vehicle capable of swimming short shore-to-shore distances while providing Marines better protection than legacy vehicles.

While critics point out that it still won't travel at a high rate of speed, Glueck argued that nearly any vehicle will likely have to rely on a connector, like the Joint High Speed Vessel, given the long standoff distances now required to protect Navy ships from as the result of the proliferation of inexpensive land-based missile technology. But, given the long standoff distances now required to protect Navy ships as the result of the proliferation of inexpensive land-based missile technology, Marines assaulting a beach will have to launch from 65 nautical miles out, or more. That means that nearly any vehicle will likely have to rely on a connector, making the ACV 1.1s inability to swim long distances quickly a moot point, he contended.

"We see connectors will be critical in the future for self-deployers and non-self-deployers," he said.

The development of a vehicle that could hydroplane at a high rate of speed and bridge that distance is technically feasible, Glueck said, but would come at the cost of protection, lethality and its ability to maneuver ashore where most of the mission will occur.

Dee said the Navy and Marine Corps will continue to look at a high-water speed capability for future iterations of the ACV, but those efforts are likely more than a decade out.

The immediate plan calls for outfitting six battalions with 200 ACVs by 2023, and modernizing enough AAVs to outfit another four battalions. That would give the service the ability to put 10 battalions ashore during a forcible entry operation.

Glueck also defended the vehicle against repeated questions from Hirono and the Sen. Roger Wicker, R-Miss., the subcommittee chairman, issippi) about the Marine Corps' decision to procure a wheeled ACV, rather than a tracked vehicle ACV.

Because of advances in technology, including independent suspension, the wheeled ACV will provide improved maneuverability over the tracked AAV,mphibious Assault Vehicle which is more than over 40 years old. Even if struck by an improvised explosive device IED that destroyed several tires, the next generation ACV will be able to drive out of a kill-zone, Glueck said.