PORTLAND, Maine — Anna Marie Klein Christie took in the windblown view of Greater Portland from the roof of One City Center on Monday afternoon.

“Over there,” the executive director of Rippleffect said, pointing toward Bayside and Back Cove, “you can see the homes of some of our kids on scholarship.”

She continued, after walking toward the view looking north and east into Casco Bay.

“Over there, you can see Cow Island, where we have our classes,” Klein Christie said.

The synthesis of views will come into play Friday, May 16, and Saturday, May 17, when Rippleffect, a nonprofit educational organization that offers outdoor leadership and expedition camps, hosts a unique fundraiser: At least 80 people, including teachers, students and a bank vice president, will rappel 12 stories, or 180 feet, down the side of One City Center to Federal Street.

Established almost 15 years ago, Rippleffect provides classes and camps for more than 3,500 students annually, including middle-schoolers in Portland and South Portland.

“We are all about moving outside your comfort zone; we call it the conscious try. The hardest thing is taking that lean back over the edge,” said Adam Shepherd, who directs marketing and adult education at Rippleffect.

One City Center building manager Mike Freed will also take the plunge.

“This will be a new experience for me,” he conceded Monday.

The first 10 will go over the side and down to the street on May 16, the rest will descend May 17, or May 18 in the event of severe weather. Shepherd said the rappelling will be a rain-or-shine event, but could be postponed in the event of thunderstorms.

In teams and individually, the rappellers have each tried to raise at least $1,000. The two spots donated to Casco Bay High School by Portland businessman Cyrus Hagge were spun into two more spots by additional fundraising.

“I’m actually terrified of rappelling, but I think it will be really, really worth the fear,” Casco Bay High School sophomore Rowan Hoyt said last week.

Hoyt, 15, has been a part of several Rippleffect camps, including rock climbing on Cow Island, which is owned by the nonprofit.

“I learned to work with teams, to trust others. You have to trust those lines are properly belayed,” Hoyt said.

Klein Christie said next week’s event, called Rappel for Rippleffect, will give fundraisers the same opportunity students get in the four-season camps and expeditions.

“Adults in the community can experience the growth,” she said. “It becomes a community celebration.”

Casco Bay science teacher Brooke Teller is one of two teachers who will rappel down One City Center.

“Probably my hand was one of the first ones in the air,” Teller said last week.

In the seven years she has taught at Casco Bay, Teller said she has been on at least three trips with seniors, which can include “Survivor”-inspired competitions to reinforce trust between students.

“I think having four or five days away and unplugged has long-reaching effects on how a senior year can be kicked off,” Teller said.

Math teacher David Burke and student Saffron Mello also earned spots to rappel. The additional spots were selected through a lottery, with those who raised the most money getting the most opportunities for their names to be chosen.

In all, students raised almost $1,300 and faculty more than $1,450. Burke raised almost $1,500 on his own.

“I realized I would be terrified, so I put my name in once, so I could say I tried,” Hoyt said.

Because the rappelling is on prom weekend, students are planning on rappelling in prom attire.

“I want a big poofy dress,” Hoyt said. “My mom was helping make a dress for this that has space for the harness.”

Shepherd said the precautions taken for what should be a 10- to 15-minute descent mean rappellers will not be in danger.

“The type of rappel you are looking at is a ‘fail-safe’ rappel,” he said. “Even a rappeller who loses their grip will not fall.”

The event is being managed by Over the Edge, established in 2003 in Halifax, Nova Scotia. The company organizes fundraisers throughout the country, adhering to standards developed by the Occupational Safety and Health Administration and the Society of Professional Rope Access Technicians.

Rappellers will be secured by two lines as they descend in pairs, with the apparatus connected to the building in two places. Anyone not about to descend will be kept away from the edge of the building, and everyone will be wearing safety gear before they reach the roof.

“It is safer than crossing the street,” Klein Christie said.

The street below will become a block party, with tables manned by sponsors, climbing walls, and 80-inch video screens to view the descents from cameras attached to the rappellers’ helmets.

Hoyt said she will bear in mind Rippleffect’s credo, that building trust in yourself and those around you is the key, when she starts down the side of the building.

“Even if you are terrified, you have to keep doing it,” she said.