the Alvin

The deep sea is not an easy place to explore. To observe the ocean below 2,000 meters (or 6,562 feet), scientists must travel in deep-sea submersibles specially designed to endure the extreme pressure. Scientists from the United States use a submersible called the Alvin. Its successful missions have ranged from the first observation of hot-water vents to finding the Titanic.

Description: U.S.-owned deep-sea submersible
Purpose: biological, chemical, and geological research in the oceans
Passenger limit: three (one pilot and two scientists and/or journalists)
Size: 23 feet 4 inches long, 11 feet 10 inches high
Weight: 37,400 pounds
Cool fact: first deep-sea submersible to carry passengers

Image credits: main image, courtesy of Woods Hole Oceanographic Institute.