Nathan Brown, an Alvin pilot-in-training, cleans a forward-looking viewport on the sub in the early-morning hours before Alvin was launched on its first research dive since 2010. It would be Brown’s first dive in Alvin. (Photo by Chris Linder, Woods Hole Oceanographic Institution)

Chris Lathan, an Alvin pilot-in-training, checks one of the pan-and-tilt cameras before the sub’s launch. (Photo by Chris Linder, Woods Hole Oceanographic Institution)

Pilot-in-training Nathan Brown (left) and WHOI scientist Susan Humphris talk with Harvard scientist Peter Girguis, chief scientist of the expedition and chair of the Deep Submergence Science Committee (DESSC). The committee advises on use of vehicles in the National Deep Submergence Facility at WHOI, including Alvin. (Photo by Chris Linder, Woods Hole Oceanographic Institution)

Veteran Alvin pilot Bob Waters (left) discusses equipment loaded onto the sub’s payload basket, including a sensor built by Don Nuzzio of Analytical Instrument Systems (right). (Photo by Chris Linder, Woods Hole Oceanographic Institution)

Alvin rolls on its track toward the A-frame of the research vessel Atlantis, with pilot-in-training Jefferson Grau riding shotgun. (Photo by Chris Linder, Woods Hole Oceanographic Institution)

Alvin pilot-in-training Jefferson Grau gets under the hood, so to speak, before a dive. (Photo by Chris Linder, Woods Hole Oceanographic Institution)

Alvin Pilot-in-training Chris Lathan peers through the pilot’s viewport as pilot-in-training Jefferson Grau prepares the vehicle for launch. (Photo by Chris Linder, Woods Hole Oceanographic Institution)

Ordinary seaman Ronnie Whims rides atop Alvin while communicating with the sub's pilot inside. The swimmers assist with Alvin launches from and recoveries to Atlantis. (Photo by Chris Linder, Woods Hole Oceanographic Institution)