DSV Alvin, the deep research submersible built by the General Mills Electronics Group, was commissioned on June 5, 1964, owned by the U.S. Navy, operated by the Woods Hole Oceanographic Institution, and named for Allyn Vine. Unlike fuel-buoyed bathyscaphes, it used syntactic foam, hollow glass microspheres in epoxy, to stay maneuverable at 17 tons, carrying a pilot and two observers in a two-inch titanium sphere sealed by a 19-inch plug hatch that water pressure holds shut. Four 208-pound steel weights take it down and are dropped for the return. In 1966 it logged 34 dives and more than 220 hours finding a hydrogen bomb lost off Palomares, Spain, which slipped from about 2,500 to 2,800 feet before a Navy robot raised it. In 1967, on dive 202, a swordfish drove its sword through Alvin’s fiberglass skin and was cooked for dinner.

On October 26, 1968, two lifting cables on the pontoon tender Lulu snapped and Alvin sank with its hatch open. All three crew escaped, and the sub lay about 4,900 feet down, 88 miles south of Nantucket, for 10 months. USS Mizar photographed it in June 1969, and after Hurricane Camille forced a retreat, the Aluminaut attached lines on August 27 and Alvin was towed to Woods Hole 40 feet underwater. A new titanium hull in 1973 led to Project FAMOUS on the Mid-Atlantic Ridge in 1974, vent discoveries on the Galápagos Spreading Center in 1977, and 380 degree Celsius black smokers on the East Pacific Rise in 1979, where chemosynthetic life thrived without sunlight.

• In 1986 it carried Robert Ballard to the Titanic with the small robot Jason Jr.
• It also gathered data at the wreck of the nuclear submarine USS Scorpion.
• A larger five-viewport sphere was forged at Ladish Forge in Cudahy, Wisconsin, starting in 2008.
• In 2014 it dove at the Deepwater Horizon oil spill site in the Gulf of Mexico.
• After a 2020 to 2022 overhaul it was certified to 6,500 meters, opening 98 percent of the seafloor.