National Geographic : 1987 Jul
New undersea sensors probe old sunken ships EEP, DARK SECRETS may be just the thing in gothic fiction, but they are formidable barriers to underwater archaeology. National Geographic photographer Emory Kristof and photo engineer Alvin Chandler have been working on the problems for years. Emory goes at a problem the way a drill goes at rock. He, Al, and their colleagues from many organizations make a widespread community of researchers, engineers, technicians, photographers, and others working together. For our part, I estimate that the Society contributes about $250,000 a year in basic development work, apart from specific research grants. A recent advance is SHARPS (sonic high-accuracy ranging and positioning system). The skeletal image of an 1883 Chesapeake Bay oyster boat (above) was made by a diver with what amounts to an electronic tracing gun, firing off 1,280 fixes-each accurate to within one inch-in less than an hour. These data points created the computer image, in effect positioning and measuring the wreck against an electronic grid. (To set a mechanical grid of pipes is slow and costly in clear water and all but impossible in black water.) Emory estimates that SHARPS does the job a thousand times faster than could an unaided diver-and SHARPS is capable of tracing a wreck in three dimensions. The other major problem is how do you get to a wreck? Divers' limits are quickly reached, and most manned submersibles are hugely expensive. Emory and his colleagues have been PRESIDENT, NATIONAL GEOGRAPHIC SOCIETY MARYLANDRESEARCHVESSELLAUNCHESROVSEAROVER developing ever smaller and less expensive ROVs (remotely operated vehicles) that can do ever larger missions-notably a recent descent (left) to the 1870 wreck of the propeller steamer New Jersey in Chesapeake Bay. Emory and such marine archaeologists as Donald Shomette of Maryland see a future of small, inexpensive ROVs guided by electronic consoles about the size and cost of a personal computer and about "as simple to operate as a color TV." This will be underwater exploration that scientists can afford, and that small companies can support technically. I am pleased that the Society is helping in this work and freely passing along the technology we've helped to develop.