Updated

With an eye for adventure and a spirit for patriotism, Paul de Gelder worked his way up through to the elite echelons of the Australian defense forces as an Army Paratrooper and later as a Royal Navy clearance diver. But he still harbored a lifelong fear of sharks – and then he was attacked by one.

In early 2009, while testing Navy equipment close to shore in Sydney Harbor, de Gelder was struck by a large bull shark – losing an arm and a leg.

“It was murky and overcast, it was early in the morning and the sun was low. That’s the best time for sharks to hunt. I was flapping around like a seal in a black wetsuit and a pair of fins and it just came up and it was a case of mistaken identity,” de Gelder, who stars in Discovery’s Shark Week special “Great White Matrix,” told FOX411. “It bit into a chunk of meat instead of human bone… I thought I was dead.”

But opening up about the attack quickly became de Gelder’s therapy, and the more he talked about it, the more he remembered.

“When it first hit me it didn’t hurt, I thought the boat just got too close. Then I looked down and saw a massive head attached to my leg,” he continued. “When it was ripping me apart in the water, I can’t even explain to you how bad the pain was – then adrenaline kicked in and was just trying to get out of the water.”

More On This...

    Ironically, de Gelder, 36, was able to channel his experience into an appreciation for the deadly predator.

    “The more you learn about sharks the more you want to spend time around them,” de Gelder explained. “It’s about knowledge, knowledge dispels fear. We need them in the oceans. It’s not our backyard.”

    In his Discovery special, de Gelder and cameraman Andy Casagrande spearhead an expedition into the deadly waters of Australia to explore a number of strange attacks in an area infested with juvenile Great Whites.

    “I loved doing this documentary. You get to share this knowledge and passion with the world,” he said. “The more you can teach people about them the more you can get people to respect animals and protect them. That’s what I want to do.”

    And de Gelder wasted no time adjusting to his “new life.” Within days of the attack, he was in hospital figuring out ways he could still jump out of planes and shoot guns having lost limbs.

    “I didn’t want to wallow in self-pity and get stuck on the slippery slope of ‘woe is me.’ I just wanted to get on with life. I need my physicality back and I knew my mind would follow,” he said, noting that he got down on the hospital floor and started with one-arm pushups within days of the incident.

    While getting back into physical shape and going back into the Navy as an instructor took several months, re-building his self-confidence as an amputee took a little longer.

    “That came from being this totally capable individual to having to rely on other people. Everywhere I go, people stare at me,” de Gelder said. “That was something I just had to learn to deal with.”

    Yet the life he leads now, he says, is actually more fulfilling than the life he led before the attack.

    “I don’t look back on it as a negative occurrence,” de Gelder added. “It just happened. People around me have much harder lives, much harder than me. It’s not worth complaining about – you just get on with it. I have big dreams.”

    “Great White Matrix” debuts as part of Discovery’s 27th annual “Shark Week” on Saturday, August 16 at 9/8c

    Follow @holliesmckay on Twitter.