THE SHARK was like a master surgeon, sinking its mouthful of scalpels into Robert Large's flesh so quickly and with such precision last year that he felt almost no pain whatsoever.

Large, a longtime volunteer diver at Camden's Adventure Aquarium, had just descended a ladder into the Shark Realm exhibit on Dec. 6, 2009, when he felt an "intense squeezing pressure" on his right leg. He thought it was a sea turtle.

"I thought to myself, 'What the heck is that?' " the married father of two said earlier this week. "I looked down and saw the shark's head and was in disbelief."

None of the visitors saw the 7 1/2-foot sand-tiger shark chomp on Large's leg that afternoon and the animal let go before it could carry him off into the 550,000 gallon tank and into news headlines across the country.

The pain that most endures, however, is that Large was kicked off the dive team, and now he's haggling over medical bills that he'd been promised would be covered, he said.

When Large, 59, of Mantua. Gloucester County, was bitten, he hauled himself out of the water and remained calm as blood oozed from holes in his wet suit. He was whisked off to Cooper University Hospital, where his injuries - rare anywhere in the world - made him an instant celebrity in the emergency room.

"Everybody in there said 'You know we see gunshot wounds and stabbings every day, but we never see shark bites. You have to let us see your wound,' " he said with a laugh.

Surgeons had to clean the deep puncture wounds from the sand-tiger's long, slender teeth and repair the damage to Large's Achilles' tendon. A few weeks later, Large returned to Cooper for more surgeries after the wounds became infected.

Large, captain of the dive team, said his granddaughter holds a little grudge at the shark that bit her "pop-pop," but despite his gnarly scars and slight nerve damage - he's almost fully recovered - he would love to be swimming in Camden right now with the sharks. But that will probably never happen again, Large said.

He was "dismissed" from the volunteer diving program in August, after almost 19 years of service.

The actions by Adventure Aquarium - which is owned by the same company the operates the Ride the Ducks tour in Philadelphia - and the nonprofit New Jersey Academy of Aquatic Sciences housed there proved to be more messy than anything the shark did, he said.

The NJAAS, which oversees the volunteer diver program at Adventure Aquarium, had promised to cover all of his medical expenses, Large said, but they paid only $20,000 of a $75,000 medical bill. Large said Brian DuVall, the academy's president and chief executive, visited him at Cooper University Hospital after the bite and said medical expenses would be covered under the "general liability insurance." As a result, Large didn't use his own health insurance.

After three months, no bills had been paid, though, and after he had concerns with the NJAAS' insurance company, he spoke with an attorney.

"He asked me, he said, 'What are you looking to get out of this?' I just wanted the bills to be paid," Large said. "He was kind of surprised because most people want blood money. I didn't want to get kicked out of the aquarium and I wasn't looking for money."

The one thing Large was trying to avoid hit him unexpectedly in August, when he received a short letter in the mail from Adventure Aquarium.

"Please accept this communication as our formal request that you refrain from any further activities at Adventure Aquarium unless you wish to visit the Aquarium as a paying customer and solely in that capacity," the letter began.

Large, who works in the health-care technology field, became a member of the New Jersey State Aquarium's volunteer dive team before the aquarium opened in 1992 and he had been diving there every other Sunday since. He'd spent 4,000 hours cleaning tanks and facilities, feeding the sea life and entertaining the guests, as well as cheering up sick children, in full scuba gear, at Children's Hospital of Philadelphia and Cooper

Large was never given a reason for his dismissal, he said, but he believes it was because he had hired an attorney to help him navigate the medical-billing issues.

"I was angry, but I was hurt more than anything," he said.

A spokeswoman for Adventure Aquarium declined to comment on Large's dismissal and said no one from the company had discussed unpaid medical bills with Large. The NJAAS' chairman referred all inquiries to DuVall, who did not return requests for comment. Adventure Aquarium is owned by Herschend Family Entertainment, which also owns the Ride the Ducks tour in Philadelphia and did not return messages left yesterday. The aquarium has received millions of dollars in government funding to expand in recent years.

After the NJAAS insurance stopped at $20,000, Large began forwarding medical bills to his personal insurance provider. Tens of thousands in bills are still being ironed out between the hospital and his personal provider, he said.

"They paid their $20,000 and that was it," Large said. "The rest was on us to figure out."

Diving in the Shark Realm was halted for several days after Large was bitten, but he said the aquarium eventually changed how and where divers entered the water to reduce initial contact with sharks. No one, he said, discussed the incident publicly, including him, but he stayed on as a volunteer despite the growing stress of mounting medical bills.

"They were worried about damage control," said Large's wife, Grace. "They did not want this getting out."

In the spring, an anonymous caller told the Daily News the aquarium was mistreating a diver who had been bitten by a shark.

In an article in the Daily News in April, Adventure Aquarium acknowledged that a diver had been bitten accidentally, saying it was the first reported shark bite there. The aquarium said the diver had recovered and had resumed diving but did not mention issues with medical bills.

Many volunteer divers, who asked to remain anonymous, say they're disgusted by what happened to Large.

"It was unfathomable that any person would have been treated that way," said one volunteer diver. "It was inhumane, impersonal, and disrespectful."

The anonymous diver said Large's dive team was furious over the dismissal but discouraged from discussing or making an issue of it among the other divers.

"They've turned their back on him," the diver said of the aquarium. "Bob was the most dedicated diver the aquarium will ever have."

Sand-tiger sharks are popular in aquariums because they're slow-moving and have protruding, snaggletoothed jaws. They're common off the New Jersey coast and can grow to 10 feet long and weigh several hundred pounds. Despite its size and menacing appearance, the International Shark Attack File has documented only 29 attacks by the species, two of which were fatal.

The shark that bit Large, along with roughly two dozen other sand-tigers and sandbar sharks, he said, is probably still cruising back and forth in the Shark Realm, eyeballing the little noses pressed against the tank.

Large said he doubts he'll ever see the shark or be allowed to dive at Adventure Aquarium again, and his family won't be paying the $21.95 admission any time soon, out of principle.

"They just basically put a stake in my heart with what they did to me," Large said, his voice choking up. "That's what they chose to do to me."