In 1956, a team of scientists convened in Washington to discuss the way forward in deep-sea exploration. They focused on the future because there was, at that point, no real past to speak of: At the time, the ocean floor was nearly as foreign to humans as the surface of the moon. We could guess what it might look like, based on the environments of shallower waters; we had as yet, however, no way to see the scene with our own eyes.
So the commission did what commissions do best: It drafted a resolution. One that, in this case, called for the United States to develop a national program to build underwater vehicles that would be capable of reaching depths never before possible. The manned mini-subs would be the maritime version of the rockets and capsules that NASA was then developing for the exploration of space: They would bring humans, for the first time, to the worlds beyond the Earth's surface.
Eight years later—on June 5, 1964—a team at the Woods Hole Oceanographic Institute commissioned the vehicle that resulted: a little sub named, in a tribute to the oceanographer Allyn Vine, Alvin. In the 50 years since then, the three-seater mini-sub—the only one shared by the Navy and the National Oceanic and Atmospheric Administration—has, the Cape Cod Times writes, "easily become the rock star of WHOI's fleet."
That's in large part because Alvin has proved to be amazingly—almost miraculously—resilient. The little sub has, as of the end of last year, taken 4,678 dives. It has spent 32,611 hours—more than 1,300 days—under the ocean's surface, with an average dive length of nearly seven hours. It has carried 14,025 humans, usually one pilot and two scientists per dive, to comb the ocean floor. It recovered a hydrogen bomb that was lost in the Mediterranean after a mid-air plane collision. It helped to discover previously unknown life forms congregating around hydrothermal vents off the Galapagos Islands. Most recently it helped to document the sub-surface effects of the Deep Water Horizon oil spill. Most famously it explored the wreckage of the Titanic.
Alvin has also proved resilient in more literal ways. During a dive it took in July of 1967, it was attacked by, yes, a swordfish. The creature became trapped in the skin of the sub, and Alvin—with the fish still stuck in its flank—made an emergency surface. (Scientists recovered the fish and cooked it for dinner.) And in 1968, the cables supporting the sub as it was being transported between two pontoon boats snapped. Alvin sank to a depth of 4,900 feet.
For most subs, that would be it: To sink is, pretty much, to die. Not for Alvin, however. In 1969, a team of ships plunged a prefabricated nylon net down to Alvin, wrapping it around the sub's hull. That allowed Alvin to be hauled back up to the surface. And when researchers opened the sub's hatch—Alvin was nearly undamaged in the sinking—they discovered ... a sandwich. A bologna sandwich, specifically, which one of the sub's occupants had stored on board before it sunk. And the meal, likely because of freezing temperatures and a lack of oxygen at 4,900 feet below sea level, showed no visible signs of decomposition—an unplanned insight into the dynamics of decay in extreme environments.
In 50 years of ocean exploration, Alvin and its work have been been cited in more than 2,000 research papers. Among them are papers that found something valuable even in Alvin's worst moment—papers that help us to understand why a sandwich can sink to the sea floor, hang out for a nearly year, and remain, as Woods Hole describes it, "soggy but edible."