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Expanding horizons: technology enhances underwater possibilities
Diving equipment has come a long way since the days of the ancient Greeks, when divers used hollow reeds as snorkels in order to sneak up on enemy ships undetected. It has changed, too, since the 1500s, when divers in France and England wore leather diving suits pumped full of air to explore depths up to 60 feet.
Since the 19th century, an increased understanding of the science of diving - how underwater pressure affects the human body - has opened the door for scientists, technicians and explorers to be inventing more advanced diving technology all the time.
One of the first significant developments in the evolution of modern dive technology was the Aqualung, the first open-circuit scuba (self-contained underwater breathing apparatus) diving system. It was developed by Emile Gagnan and Jacques Cousteau in 1942 and consisted of a high-pressure diving cylinder and a diving regulator that supplied the diver with breathing gas at ambient pressure.
Today, as diving technology and materials become more and more sophisticated, Jean-Michel Cousteau, like his father, is at the cutting edge of discovering, designing, developing and experimenting with models and designs that have the potential to take divers deeper, longer.
The Ocean Adventures team dives in three different modes, says chief diver Blair Mott. There is open-circuit scuba, the traditional
Rebreathers have been around for a long time, but in the past they were mostly used for military operations. Now, with exciting new technology that allows divers to monitor and control their gases and gas mixes, more and more professional and recreational divers are using them. Rebreathers work by recycling the air that the diver is breathing out and cleaning out the carbon dioxide that can become toxic over time. This recycling of air allows divers to stay underwater longer because their gas tanks last a lot longer than those of divers using open-circuit systems. A diver using a rebreather only consumes the small amount of oxygen that his or her body actually needs, in contrast to an open-circuit system, which vents a diver's entire exhaled breath into the water, including all the unused oxygen. Also, because the rebreathers can regulate the correct mix of gases for whatever depth the diver is at, the decompression time is shorter.
Another benefit of rebreathers is that they do not release bubbles like open-circuit scuba systems do. Therefore, divers can swim silently around coral reefs and marine animals without scaring them off. This is particularly useful for underwater photographers and filmmakers trying to get close enough to capture exceptional underwater footage.
"It's almost 'noninvasive' diving," says Mott. "Because if you think about a team of bubble-blowers, or open-circuit divers, going into an area, it's very possible that they could be making more of an impact on the natural environment around them than if they were diving with a rebreather."
"We, as filmmakers, love them," says Ocean Adventures expedition leader Don Santee. "It's a lot lighter than carrying all the gas that you need for open-circuit. So, with rebreathers, now our durations are a lot longer, yet we have smaller units on our backs. And because there are no bubbles, after a while the animals just kind of accept us. Once we've been down there for a half hour to an hour, they just go about their business as if we weren't even there. We've gotten some pretty amazing stuff that way."
The JMC SuperMask
Designed by Kirby Morgan and Jean-Michel, the JMC SuperMask is a lightweight, versatile full-face mask made of plastic and silicone. The removable mouth pod is designed to allow the diver multiple breathing gas options, giving the diver the capability to buddy-breathe, to use a snorkel, to perform an in water gas switch or to insert communications devices. In addition, the removable mouthpiece serves an important safety function in case a diver loses consciousness.
"Normally," says Matt Ferraro, a marine operations specialist, "if a diver lost consciousness underwater, the regulator would come out of his or her mouth and the diver would aspirate [inhale] water and drown. With the SuperMask there's a completely dry airspace around the mouth, and there's a pod connected to the mask so that if you did happen to pass out or get knocked out for any reason and the regular mouthpiece came out of your mouth, you would still stay dry and be able to breathe. This way the diver could be rescued or would regain consciousness and be able to help himself or herself out."
Another exciting feature of the SuperMask is that it is designed to accept various wireless and hardwire communications systems and devices. The Ocean Adventures team has communications built directly into the mask, including a microphone to speak into and an earpiece for hearing. The team is able to transmit from diver to diver as well as from diver to the dive operations station above the water. This way, divers can coordinate with one another for filming and other purposes, and they can send and receive alerts to and from the team members above the water about emergency situations and weather conditions.
The Ocean Adventures team dives with custom-made Launch Pad fins together with the Oscillating Propulsion System, all designed and manufactured by Force Fins.
Page created 3-22-06. © 2006-2009 KQED and Ocean Futures Society. All rights reserved.