Gunnery Sgt. William "Spanky" Gibson loves to show off his leg.

The high-tech contraption of titanium, carbon-fiber weave and computer chips costs more than $75,000 and he's got six more like it for every occasion — running or biking or just walking around his base.

"Why would someone want to shy away from it?" asked the barrel-chested Marine. The logo he had drawn on his prosthetic leg sums up Gibson's attitude. The words, "When quitting is no longer an option, you are halfway there," wrap around a Marine Corps logo.

Gibson, who lost his leg after an Iraqi sniper shot his knee, wants to show people that just because he's an amputee doesn't mean his life is over. He and three other Marines seriously injured in the Iraq war are competing Saturday in the Admiral's Cup race at Naval Base Ventura County at Point Mugu. They hope that after competing in the 400-meter swim, 9-mile bike ride and 3-mile run, their example will prove life goes on.

They are each determined, positive and proud and never question if they should have enlisted.

The rate of amputations in the Iraq war is twice that of any previous war, although the rate of survival is also higher because of the medical care and body armor.

The four Marines, called Team Semper Fi, are touring the country to raise awareness as well as money for the Semper Fi Fund, a private, nonprofit group that provides financial support to Marines wounded while fighting.

Dan Lasko had never heard of the Semper Fi group when two women walked into his room at Walter Reed Army Medical Center before Christmas 2004 and gave him a few thousand dollars to buy gifts.

Lasko, who coincidentally enlisted on Sept. 11, 2001, was manning a .50-caliber weapon on an armored vehicle in March 2004 when a roadside bomb blew up, which led to the amputation of his left leg at mid-calf.

Learning how to use his new leg was challenging, complete with phantom pain and tumbles in the shower, but he never once thought things wouldn't work out.

"Can't do' and cripple' are not in my vocabulary," said Lasko, 24. "Just because you lost a limb doesn't mean you lost everything."

If anything, Lasko said, he's a happier person now because he appreciates being alive that much more.

Doctors were finished with Bacillio Santellana when they amputated part of his right foot after a roadside bomb blew up during his second tour in Iraq. Although he could walk fine, he wanted to be able to run again, even if he wasn't into the sport at the time.

"I'm still young and wanted to be able to run after my kids one day," said Santellana, 23.

He opted to have a second surgery that took off his foot above the ankle so movement would be more fluid. Within three months, he did a 3-mile race.

Gibson is aware that he and his fellow racers have what might seem like an unimaginably positive outlook on their experiences.

During his time in rehabilitation, he talked with plenty of other troops struggling with how to move on without a limb.

The biggest worry on the minds of young troops was how this was going to affect their dating lives and if women would think they were weird.

He tried to get them to accept their new station and go forward.

"I tell them your life has been altered, but it is not ended," said Gibson, 36, who is still enlisted.

He had to have two surgeries: one to remove his foot and another to amputate his leg just above his knee after complications arose.

It hurts sometimes when he runs, but he does what any other athlete would do — he pops a few Aleve.

Medical conditions continue to haunt him. The bone above his stump has not healed properly, and he thinks he'll have to have an additional 4 inches of his leg amputated in the next year or so.

So what will he do after a third amputation? Gibson said he wants to take up surfing again after he's done with rehabilitation.