It's been more than 50 years since the first and only human expedition to the deepest part of the sea. Dr. Sylvia Earle, world-renowned marine scientist, president of the Sea Alliance, and founder of Deep Ocean Exploration and Research (DOER Marine), which pioneers technologies for scientific ocean research and exploration, discusses how the technology to take humans directly into the sea for research and exploration has evolved over the years and what the future holds for human exploration.