Thrusters
		Ballast Tanks
		Ergonomics
		Lift Point
		In September 2021, Alvin completed the final phase of an overhaul funded by the National Science Foundation that greatly expanded its capabilities and now enables it to travel 6,500 meters below the sea surface.
		Viewports
		Manipulator Arms
		
		Life Support
		Personnel Sphere
		Frame
		Sample Basket
		Electronics
		Explore what's new about the upgraded and improved Alvin.
		Sail
		Cameras & Lighting
		Control Systems
		Syntactic Foam
		Lateral Thruster
		Hull Penetrators
		Thrusters Three aft thrusters drive Alvin forward and backward and can also be used to turn the sub. Five of the sub's seven thrusters can also be jettisoned in case the sub becomes entangled.
		Rebuilding Alvin: Robert Waters
		Rebuilding Alvin: Carroll/McCartney
		Rebuilding Alvin: Harvey/Miller
		Rebuilding Alvin: Phil Santos
		Syntactic Foam Carefully formed blocks of syntactic foam, a material composed of hollow glass spheres embedded in an epoxy resin, provide Alvin's buoyancy. This specialized material will not change shape under extreme pressure and provides a secure mounting surface for lights, cameras, and other components.
		Rebuilding Alvin: Al Suchy
		Rebuilding Alvin: Dutch Wegman
		Lift Point The upgraded Alvin weighs nearly 45,000 pounds—about 8,000 pounds more than the previous sub. As a result, the sub's frame and the lifting gear on its support ship Atlantis had to be either reconfigured or rebuilt to handle the weight during the delicate task of launch and recovery.
		Rebuilding Alvin: Kakani Katija Young
		Rebuilding Alvin: Patrick Hennessy
		Rebuilding Alvin: Robert Waters
		Sail Alvin's sail is painted international orange to improve its visibility and contains a set of controls to drive the sub on the surface. A carbon fiber "bathtub" inside keeps water out of the personnel sphere if the hatch is opened on the surface.
		Rebuilding Alvin: Ben Pietro
		Lateral Thruster The upgraded Alvin has new sideways-mounted thruster on the sail—the aft section contains a second. Both are integrated into the new digital control system to give pilots more control over the sub's position and lateral movement.
		Cameras & Lighting Alvin is equipped with five high-definition cameras and broadcast-quality digital recording equipment. Two cameras are mounted on pan-and-tilt units controlled by the observers. High-intensity LEDs provide exterior lighting. The sub's support ship, Atlantis, is newly equipped with matching video duplication and science video systems.
		Let There Be Light in the Dark Depths
		Personnel SphereAlvin's titanium personnel sphere is one of the most perfect large spheres ever built. It is three inches thick—one inch thicker than the previous—and capable of withstanding pressures down to 6,500 meters, 2,000 meters deeper than the old Alvin.
		Rebuilding Alvin: Kurt Uetz
		Manipulator Arms Both of Alvin's manipulator arms have been upgraded with an additional "shoulder" joint to give each one expanded reach and greater freedom of movement. The added joint also allows both arms to be moved completely out of the field of view of the forward viewports to improve visibility.
		Hull Penetrators
		Sample Basket A larger basket on the front of Alvin can hold up to 400 pounds—twice the previous capacity—and measures 16 square feet—33 percent larger.
		Rebuilding Alvin: Jefferson Grau
		Rebuilding Alvin: Jefferson Grau
		Viewports The new Alvin has two additional viewports facing forward for a total of five in the personnel sphere. Three 17-inch, forward-looking viewports provide a wider, overlapping field of view that improves seafloor observations and situational awareness. The two side viewports are 12 inches in diameter.
		Viewports
		Rebuilding Alvin: Chris Lathan
		Control Systems Alvin's control systems are now digital and designed to provide scientists and pilots with an integrated platform from which to monitor the status of the sub and scientific activities simultaneously. The system is also designed to incorporate new sensors and equipment as deep-sea research capabilities evolve.
		Alvin Gets an Interior Redesign
		Ergonomics The interior of Alvin's personnel sphere is 6 feet 10.5 inches in diameter compared to 6 feet 6 inches previously—giving it 20 percent more interior volume. A team of pilots and scientists redesigned the interior with an eye toward providing three people more comfort on dives lasting up to eight hour.
		Rebuilding Alvin: Elder/Fournier
		Life SupportAlvin carries 12 bottles of oxygen, a CO2 scrubber, four Emergency Breathing Apparatus masks, two fire extinguishers, and an atmospheric monitoring system. Two of the bottles are used during a dive with a third as spare; the other nine hold a 72-hour supply if the sub needs to remain submerged for an extended period.
		Frame
		Rebuilding Alvin: Popenoe/Lewis
		Hull Penetrators Fourteen electrical and six optical penetrators provide power and high-bandwidth data links through the personnel sphere to systems and instruments outside.
		Rebuilding Alvin: Geoffrey Ekblaw
		Frame The new Alvin uses the previous sub's titanium frame, but with modifications to accommodate upgrades such as the new personnel sphere and syntactic foam. It gives the sub rigidity and plays a critical role in keeping Alvin structurally secure during launch, recovery and dives.
		Rebuilding Alvin: Paul Keith
		Rebuilding Alvin: Rick Sanger
		Rebuilding Alvin: Will Sellers
		Electronics Redundant motor controllers and power distribution circuits have been upgraded and integrated into the sub's digital command and control system. Back-up analog circuits give the pilot full control over the sub even with a complete loss of computer systems and data feeds.
		Rebuilding Alvin: Loral O'Hara
		Ballast Tanks Eight titanium spheres containing either water or high-pressure air are used to control Alvin's overall buoyancy at depth or on the surface. A trim system allows the pilot to fine-tune the sub's orientation during transits across sloping bottom terrain or to improve viewing angles while working.
		Rebuilding Alvin: Brian Pepin