Alvin has spent 47 years exploring great mysteries of the deep ocean. Many of the sub’s 4,664 dives have made history: Alvin surveyed Titanic’s wreckage in 1986, the first known hydrothermal vents in the 1970s, and the BP oil spill in 2010. But scientists who have crammed into its six-foot-diameter titanium cabin know there is room for improvement. Alvin cannot withstand pressure at depths greater than 2.8 miles, leaving nearly 40 percent of the seafloor off-limits. And the compact interior can be tough on passengers: Imagine sitting cross-legged on a thin cushion for up to nine hours at a stretch.
This September Alvin’s operators at Woods Hole Oceanographic Institution (WHOI) received approval for a dramatic $40 million makeover. Performance upgrades include new buoyancy foam that can withstand the 9,552 pounds per square inch of pressure that exists four miles down—giving scientists access to 98 percent of the ocean. As for endurance, Alvin’s lead-acid batteries will be replaced with lithium-ion batteries allowing up to 12 hours of operation.