Last night, a few minutes after 11:00 p.m., our expedition ship, the Ocean Voyager, slowly pulled out of Boston Harbor, heading 950 miles due east for the Titanic. Landlubber that I am, I found myself thinking, as I watched the comforting, familiar city lights recede into the darkness, Am I crazy? What am I doing here?

That, I discovered, is a sentiment shared by at least some of my 54 fellow passengers—especially those of us who have never voyaged for four days to an isolated spot in the Atlantic Ocean, 450 miles from the nearest point of land.

One of my shipmates, a Seattle photographer and writer named Paul Souders, has traveled and worked in the Kalahari Desert, the fjords of southeastern Alaska and the Siberian Taigonosk Peninsula. But the thought of bobbing around in the middle of the North Atlantic made him consider, at least for a second, the wisdom of jumping ship just before the Ocean Voyager left port.

Most of the crew members, however, are well-used to long stretches out at sea. To many of them, this trip is "just another day at the office"—except that, of course, it isn’t. We’re headed for the Titanic, the most famous shipwreck in the world, on a vessel packed with millions of dollars’ worth of remote-controlled robotic cameras, fiber-optic cable, satellite equipment and video production gear.