Alvin - the submarine that found the Titannic - will be 50 years old next year. They are installing lithium-ion batteries that will give it even more range. It will be able to explore 98% of the ocean bottom then.
Harry - When I taught oceanography many of my lessons included information collected by Alvin.
From PlugIn Cars Magazine -
No, it doesn't look much like an electric car, but there are some remarkable parallels. The famous deep-sea submarine Alvin, which explored deep-sea vents and the wreck of the Titanic, has made 4,600 dives and remains a state-of-the-art submersible despite its 1964 construction date. Alvin, owned by the Navy and operated by the Woods Hole Oceanographic Institute (WHOI), has just undergone a $41 million upgrade that will allow it to reach 6,500 meters and explore 98 percent of the ocean’s floor.