Ms. Maxwell had negligible experience as an environmental activist. Her preferred method of oceangoing was aboard a luxury yacht, which, according to Mr. Mason, was for her the pre-eminent symbol of “status and freedom.” It was through boating that she drew her inspiration for the foundation.

She spent much of her time in the late 1980s on the Lady Ghislaine, a nearly 200-foot boat owned by her father, the media mogul Robert Maxwell. It had a Jacuzzi, a sauna, a gym and private disco. Deep in debt, he bilked the pensions of thousands of his employees, and his body was discovered in the ocean off the Canary Islands, where he had taken the Lady Ghislaine in 1991.

The death was ruled an accident. The family reportedly lost almost everything, including the boat.

Ms. Maxwell, then living in New York, became known for her romantic relationship with Mr. Epstein, who was an all-purpose adviser for the billionaire Leslie Wexner. (Mr. Wexner said in a letter to the Wexner Foundation that, in 2007, he discovered misappropriation of his funds by Mr. Epstein.)

One of Mr. Epstein’s duties was handling contracts for the Limitless, a mammoth yacht bought by Mr. Wexner and designed by Bannenberg & Rowell. Ms. Maxwell was eager to get aboard when it was finished but never did, according to Craig Tafoya, its former captain.

“Ghislaine would always call me and say, ‘I’m coming down to use the boat with some friends. I would always tell her, ‘I have to call the owner. I can’t just let you on the boat.’ And she would never show up,” said Mr. Tafoya, who took this to mean that she never got permission. “She did that half a dozen times. And in talking to a guy who worked for Bannenberg, he said, ‘she does that all the time. She does it when she’s in front of all her girlfriends and wants to brag that she can go use someone’s yacht.’”

Her Plan B