Captain Don Walsh stops by the Googleplex to discuss: "Going the Last Seven Miles - a Personal Odyssey."
Don Walsh and Jacques Piccard were the first people to go to the Marianas Trench over 50 years ago.
Only James Cameron has been back since.
Don jokes that he should have written a book called "The Right Stuff, Wrong Direction", alluding to how much public interest space has generated related to the deep ocean, our own innerspace.
He advises the XPRIZE, is an Ocean Elder, and has captained a nuclear submarine.
Next year he'll be on a National Geographic Lindblad expedition through the Northwest Passage.