It does bear mention, however, that Carpenter's pioneering spaceflight was just the precursor (not to diminish his space experience at all) of his next milestone in exploration: 1965's undersea jaunt aboard the habitat Sealab II in Scripps Canyon, just off the coast of La Jolla, California. This period in Carpenter's career directly contributed to how astronauts are trained for modern-day International Space Station (ISS) missions, but sadly these kinds of things get lost in history. Let's briefly revisit Scott Carpenter's love affair with the sea. Why did it capture his imagination, and why did he enter it so eagerly?
Man's exploration of the sea cannot yet be compared to manned spaceflights since the latter involve sophisticated equipment and advanced scientific techniques. Yet I have found that the problems of putting man beneath the surface of the sea are related in a number of ways to the task of making him effective in space. In the underwater program, for instance, we must select and train crews, design new types of capsules, devise special tools, provide a viable atmosphere, plan and conduct a schedule of unprecedented scientific experiments – requiring extensive extra vehicular activity – and conduct physiological and psychological tests on man outside his natural environment. Man leaves his natural environment not without some hazard, and a few surprises since he has become conditioned to it through eons of existence in the earth's atmosphere.Carpenter continued that unlike space, the undersea environment was teeming with diverse life. The crew even worked with a “highly trained and friendly” dolphin, Tuffy, who on occasion delivered supplies (a living “cargo ship,” if you will). But the environment did have some similarities to life in space. Basic tasks such as cooking posed a challenge due to the habitat's unique atmosphere. Personal space was described as “extremely limited.” And the crew, just like astronauts aboard a space station, was able to complete 44 scientific experiments inside and outside the habitat.