Early career Alvin, first of its
ship class of
deep submergence vehicle (DSV), was built to dive to . Each of the
Alvin-class DSVs have different depth capabilities. However,
Alvin is the only one seconded to the
National Oceanic and Atmospheric Administration (NOAA), with the others staying with the
United States Navy.
Alvins first deep sea tests took place off
Andros Island, the Bahamas, where it made a successful 12-hour, uncrewed tethered test dive. On July 20, 1965
Alvin made its first crewed dive for the Navy to obtain certification. On July 6, 1967, the
Alvin was attacked by a
swordfish during dive 202. The swordfish became trapped in the
Alvins skin. The attack took place at below the surface. The fish was recovered at the surface and cooked for dinner. The aircraft had ditched September 30, 1944, during carrier qualifications, with the pilot surviving. Severe weather prevented the recovery of
Alvin throughout late 1968, but it was photographed at the bottom of the Atlantic Ocean in June 1969 by a sled towed by
USS Mizar.
Alvin was found to be upright and appeared intact except for damage to the stern. It was decided to attempt recovery; although no object of
Alvins size had ever been recovered from a depth of , recovery was "deemed to be within the state of the art". In August 1969, the
Aluminaut, a DSV built by
Reynolds Metals Company, descended to
Alvin but had trouble attaching the required lines, and side effects from
Hurricane Camille were producing worsening weather, causing the team to return to Woods Hole to regroup. The second attempt started on August 27, and
Aluminaut was able to secure a line and safety slings to
Alvin and wrap a nylon net around its hull, allowing it to be hauled up by
Mizar.
Alvin was towed, submerged at , at a speed of , back to Woods Hole. The French provided submersibles
Archimède and
CYANA. A total of forty-four dives were completed that succeeded in defining the crustal accretion zone in the floor of the rift valley.
Hydrothermal vents Marine geologists using
Alvin in the
Pacific Ocean discovered deep-sea
hydrothermal vents and associated biologic communities during two expeditions to ocean
spreading centers. In 1977 scientists in
Alvin discovered low temperature (~20 °C) vents on the
Galapagos spreading center east of those same islands. During the
RISE expedition in 1979 scientists using
Alvin discovered high temperature vents (380 °C) popularly known as '
black smokers' on the crest of the
East Pacific Rise at 21° N. These discoveries revealed deep-sea ecosystems that exist without sunlight and are based on
chemosynthesis. A new robotic arm was added in 2006.
2008 upgrade In June 2008 construction started on a stronger, slightly larger personnel sphere which was used to upgrade
Alvin, before being used in an entirely new vehicle. The new sphere was designed, and then forged from solid titanium ingots in two equal halves at Ladish Forge,
Cudahy, Wisconsin. Then the 15.5 tonnes of titanium was machined and assembled, utilizing five view ports (instead of the previous three) and is designed for depths of over , where
Alvins original depth limit was . This, along with a general upgrade of support systems, instruments and materials. These upgrades allow
Alvin to reach 98% of the ocean floor.
2011 to 2014 rebuild After one last dive to assess damage to the
Gulf of Mexico's seafloor after the
Deepwater Horizon disaster,
Alvin was refitted further, starting January 2011. Alvin began an extensive rebuild, which featured new cameras, lighting, and an enlarged titanium personnel sphere. This three-and-a-half-year effort to upgrade the vessel implemented the core infrastructure to eventually increase its depth capability from to . In 2014, an extensively refitted
Alvin conducted verification testing in the Gulf of Mexico, and was certified to return to service. In March and April 2014,
Alvin was used to explore the site of the 2010 Deepwater Horizon oil spill.
2020 to 2022 upgrade Starting in 2020, the second phase to upgrade Alvin for operation began; the 2014 rebuild with new, larger titanium, personnel hull and rebuilt structural frame being the first phase. In this phase, Alvin received new titanium ballast spheres, a second Schilling manipulator arm, a 4K imaging system, several new syntactic foam modules, an upgrade to the hydraulic system, and new thrusters. During 2022, Alvin successfully completed sea trials and was certified for operating down to 6,500 meters. ==Current status==