FORT JACKSON, S.C. — Navy sailors are trading their sea legs for dry land combat skills to help them survive in war zones, and the training is coming from an unusual place: the Army.

The Navy is sending thousands of men and women to Iraq and Afghanistan to relieve pressure on Army and Marine ground forces, some of whom have faced repeated deployments to the region.

"Hit the ground and brace yourself with your weapon!" Army senior drill instructor Warren Brown yelled at a dozen Navy trainees slithering across a mud-soaked field. "Look around, pick yourself up and go! You're under fire!"

After struggling up from the mud with her M-16 in hand, Petty Officer 2nd Class Jade Permenter acknowledged Brown's instructions to keep her head and butt down because it might save her life someday.

"This is excellent training, really. It will be very helpful. I'm headed to Iraq — I need this," said the 34-year-old reservist nurse from Columbus, Ohio.

Petty Officer 3rd Class Waheed Sahraie, 24, said he volunteered for the training before heading to Iraq.

"Personally, I was motivated by 9/11," said Sahraie, of Slate Hill, N.Y. "But I think we're all doing this to ensure that our fellow soldiers, sailors, airmen and Marines come home safely."

Up to 10,000 sailors are expected to come through Fort Jackson during the coming months, said Cmdr. Kevin Aandahl, spokesman for the Navy's Education and Training Command in Pensacola, Fla.

While the Navy is closely tied to the Marines Corps, the Marines' training bases didn't have the facilities to provide combat training for thousands of sailors in a short time, Aandahl said.

That led the Navy to single out Fort Jackson, the Army's largest training base.

The training is an opportunity to blend services — part of the Pentagon's move toward getting the Army, Navy, Air Force and Marine Corps to cooperate and drop duplicative services, officials said.

"This is very much the way the Department of Defense is going — all four services are learning to work together," said Army Lt. Col. Doug Snyder, who is in charge of the training program. "It's sharing of responsibilities, and no more of 'This is my lane, stay out of it.' "

So far, about 1,200 sailors have gone through the intense, two-week course crammed with basics such as learning to fire M-16 rifles, toss hand grenades and conduct house-to-house patrols while weighted down with body armor — skills not called for aboard ships.

"It's not about being Army or Navy anymore. The name of the game is staying alive," Brown said.

Lt. Cmdr. Ed Moninger, 37, of Seattle, is a reservist headed to Kuwait to manage supplies. "In the Navy, we're very technical, very specialized in our jobs, but the Army is much more physical," Moninger said.

Fort Jackson's commander, Brig. Gen. James Schwitters, said the course was designed to give sailors "battlefield awareness."

"It's how to survive, if they need to survive. It's knowing what to do, what action to take to support those around you and not to do things that would make a situation worse than it is," Schwitters said.

Still, while Army basic training usually lasts about nine weeks, the transplanted sailors are given only two weeks of training, putting in 12 to 16 hours a day.

And while fresh Army recruits spend two to three weeks training with their weapons, the sailors have just two or three days to acquaint themselves with a 9 mm pistol or M-16 rifle.

"It's like putting a fire hose in your mouth," said Snyder. "It's remarkable what we are putting these sailors through."