Civilians Pay for Extreme SEAL Experience

"Nightline" embedded for a week with the Extreme SEAL Experience, which is run by former Navy SEAL Don Shipley. Here, Shipley gives a briefing on how to rappel. Many of the men who attend will never have been so physically and mentally challenged. "You never remember the easy things you do in life," he tells his SEALs. "You only remember the hardship. Really rough stuff." (Ely Brown/ABC News)