Previously, we told you about the SharkSkunker, a shark repellent device available in a variety of delivery forms. Recently, I caught up with David Schneider -- the SharkSkunker's eternally-smiling inventor -- and talked with him about his product. For nearly three hours, we discussed the SharkSkunker, the numerous hurdles he's had to overcome to bring the product to market, and what's in store for the future.

I met David at his home (coincidentally, he lives 2 blocks from me), and we walked to a local coffee shop to talk. Dressed in a blue shirt and khaki shorts, and looking something like a sunburned Viking, sans horned helmet, David is both articulate and passionate about the SharkSkunker. After ordering a coffee and grabbing a seat, David immediately launched into a discussion about the device. I didn't even need to choose one of my carefully prepared questions.

"I had the original idea in 1980, when I was a senior in high school," he began. After watching a TV special about the Moses sole -- a fish that secretes a substance called paradaxin, which appears to repel sharks -- David had a brainstorm. While popping air-filled packing bubbles and talking with his father, David mused that divers should wear wetsuits covered with paradaxin-filled bubbles. That way, if a shark bit down on a wetsuit, it would get a mouthful of the dreadful stuff and swim away. David's dad, an IBM employee who wrote patents for fun (don't ask!), applied to the patent office for the idea, and the course of David's life was set.

Shortly thereafter, research into paradaxin revealed that it was chemically similar to sodium lauryl sulfate (SLS), a common foaming ingredient in many household cleaners, toothpastes, and shampoos. (I checked and, indeed, SLS is the second ingredient in my wife's shampoo.) Easier to work with than the all-natural paradaxin, SLS is a viscous liquid that, according to David, seems to coat the gills of sharks, rendering them unable to breathe. Understandably, this causes them to flee.

Soon, David realized that a wetsuit was not the most effective repellent-delivery method; after all, once a shark bites down, it's a little late to "repel" the attacking animal. Therefore, he began brainstorming about a more appropriate delivery method. Recognizing that individuals drifting in life rafts complained about being bumped by sharks while waiting for rescue, David decided to use SLS (cheaper and more stable than paradaxin) and develop it as a dry, time-release formula. That way, it could be stored on life rafts, and people in need could drop the dry formula overboard to chase away sharks. A brilliant and simple idea.

In the late 1980's, David signed a contract with Givens -- in his words, "the Cadillac of life rafts" -- to include his shark repellent on each raft sold. Things were looking good. However, just before production, the EPA stepped in and dithered for 3-and-a-half years while trying to determine the safety of the product. Moreover, Givens fell ill and focused his energy on his health rather than his life rafts. Time crawled by, and since the Givens family owned the contract incorporating David's invention into their life rafts, there was nothing David could do to move forward. He was stuck.

Eventually, Givens died, and David received the terminated contract back from the Givens family. Further, the EPA finally allowed the limited use of the repellent for rescue and "shark-involved water emergencies": casual beach-goers, for example, should not be carrying SharkSkunkers to the beach and using them on a regular basis. David was free to pursue his dream.

However, he decided to change directions slightly. Feeling his time-release formula was simply too slow to be effective, he decided to pursue something akin to a pepper spray for sharks. "Fifty-five percent of shark attacks are 'bump-and-runs' on the shoreline, in shallow water," David told me. Citing shoreline shark attack after shoreline shark attack, David decided to focus on creating an on-demand system that rescuers could use to shoo away sharks immediately.

He decided to load the chemical repellent into a pony tank that would be encased in a flotation device. The pony tank would have an on-demand valve allowing users to discharge the repellent at will. Moreover, since the unit was buoyant, it could be tossed to a victim in the water and used as a flotation device. When he had completed the new design, he had developed the SharkSkunker as we know it.

Capable of discharging the repellent in a powerful 4-foot blast, David began reaching out, explaining his invention, and asking if people were interested. The SharkSkunker could be marketed to lifeguards, he felt, or oil companies, cruise ships, rescue services, navies, fishermen, or even spearfishermen. Basically, anyone who risks a visit from a shark is a potential customer.

Soon, the US Navy invited him to visit their procurement officer in Norfolk. Prepared to meet with one person, David was surprised when he was heralded into a room filled with a dozen officers, who listened to his presentation and then grilled him about his device. Ultimately, they said they'd like to purchase the SharkSkunker, but their budget wouldn't allow testing of the units. If David could produce a short video, documenting the efficacy of the unit's delivery and demonstrating that sharks were, in fact, repelled by the chemical, they'd buy it. No sweat, right? David just needed to shoot some footage of sharks fleeing the spray.

That was 8 boat trips ago. As it turns out, David has been stymied by this seemingly simple request. Although he's gone hunting for sharks in the Bahamas and off Florida's east coast, it seems that sharks -- much like police -- are rarely around when you need them. And when he has seen sharks, his footage has been obscured by the cloud of repellent he shoots. In other words, the discharge is so powerful that David unintentionally masks the sharks swimming away.

Of course, there have been other problems, as well, not the least of which has been bureaucratic ineptitude, and the fact that the existing threads in the pony tanks he uses are not perfectly compatible with his system. For those who think that bringing a new idea to market is simple, just ask David. Remember: he first had his brainstorm in 1980.

However, good news abounds for the inventor of the SharkSkunker. Luxfer -- the manufacturer of the pony tanks he uses -- has agreed to do a run of specially-threaded tanks for him. Recently, the Indian Navy expressed interest in the SharkSkunker and has repeatedly requested that David provide them with some working units. Additionally, Japan's Air & Sea Rescue wants the units for their rescue workers, and Sunoco Oil Company has requested units to protect their divers working near oil rigs.

But even more exciting than these potential contracts is this: the video crew from Discovery Channel who develops Shark Week is visiting next month to help him capture the necessary underwater footage. Unlike in previous filming episodes, this time the group plans to use two cages -- one with the repellent, and one with a camera crew -- to film the SharkSkunker in action. That is, if they can find sharks...and keep them around. "Sharks are just fish," David says. "They hear a noise, get frightened, and they swim away." Although they face some big challenges when filming, if there's anyone capable of capturing this footage, it's the crew from Discovery Channel. And once David has that footage proving his device works, he can sit back and relax. Finally.

Right now, things look good for David Schneider. Professional camera crews are going to help him capture some much-needed footage. The canister manufacturer is preparing a run of specially-threaded tanks. The Indian and Japanese governments are interested in contracting with David, and the US Navy is almost ready to, as well. Moreover, David and his wife are expecting their first child. The next year will prove to be very interesting for David...and the SharkSkunker.

So, despite all the obstacles, it's no wonder David wore that huge smile on his face while we were talking. He can see the light at the end of the tunnel -- a tunnel he has been inside for more than 25 years.