Willcox was recently released from a jail in St. Petersburg after spending over two months in Russian custody. Willcox and 29 others aboard the Arctic Sunrise ship were detained in September following an attempted protest against offshore drilling in the Russian Arctic.
All 30 were initially charged with piracy and could have been sentenced to 15 years in prison if they were convicted. The charges were reduced to "hooliganism," which still carries a sentence of up to seven years.
Nearly all of the activists have been released on bail and Greenpeace lawyers are "optimistic" that the 26 from other countries will be able to leave Russia pending trial, reported the Associated Press.
"The hardest thing was the uncertainty, the anxiety, the damn fear," Willcox told the AP. "Everybody lost weight during the first three weeks, and not because of food, but because of stress."
Bonnie "Prince" Billy is the stage name of Kentucky-based artist Will Oldham. "Black Captain" originally appeared on his 2011 album "Wolfroy Goes to Town."