At first look the ghostly image resembles the surface of the moon, with innumerable striations in the seabed, as well as craters caused by boulders dropped over millennia from melting icebergs. In a tricked-out trailer on a back lot of the Woods Hole Oceanographic Institution (WHOI), William Lange stands over a blown-up sonar survey map of the Titanic site-a meticulously stitched-together mosaic that has taken months to construct. Never have we taken the full measure of what’s down there.

Never have we been able to grasp the relationships between all the disparate pieces of wreckage. Yet we’ve mainly glimpsed the site as though through a keyhole, our view limited by the dreck suspended in the water and the ambit of a submersible’s lights. In recent years explorers like James Cameron and Paul-Henry Nargeolet have brought back increasingly vivid pictures of the wreck. From time to time, beginning with the discovery of the wreck in 1985 by Explorer-in-Residence Robert Ballard and Jean-Louis Michel, a robot or a manned submersible has swept over Titanic’s gloomy facets, pinged a sonar beam in its direction, taken some images-and left. Weird colorless life-forms, unfazed by the crushing pressure, prowl its jagged ramparts. The wreck sleeps in darkness, a puzzlement of corroded steel strewn across a thousand acres of the North Atlantic seabed. This story appears in the April 2012 issue of National Geographic magazine.

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