ATHOL - Rafters drop into the throat of the gargantuan green fiberglass monster that is Ricochet Rapids - and descend into extreme darkness.

Once inside the massive, snaking structure, the twists and turns are impossible to anticipate or see ahead as riders "ricochet" from side to side.

Suddenly rafters hit an extreme, but smooth, drop and burst into daylight. The raft banks high on the walls of the enclosed MEGA tube, swooping up and down.

At 20 feet in diameter, the MEGA tube is twice the girth of the rest of the green slide.

"Tube is better than no tube," said 13-year-old Jerrod Mahoney, of Buckley, Wash., on Friday.

After the MEGA tube, it's back into the darkness, with maximum speeds reaching 20 mph.

"You don't see what's coming up next," said Aaron Galvez, 13, of Liberty Lake. "It's awesome."

Galvez and Mahoney were among the first to experience Ricochet Rapids.

Silverwood Theme Park opened it Friday. It's a new family raft slide that cost $2 million to build, and it's part of the Boulder Beach Waterpark.

The 737-foot long slide is longer-than expected, and it's so fast it's hard to remember exactly what happened during the 56 seconds.

And it's next to impossible to resist another trip back to the top of the mountain for another journey down. The raft descends a total of 70 feet in elevation, and nobody stays dry.

The number of people in the raft and the displacement of weight can create a different experience each time. Four to six people fit into the circular raft.

The slide was built by Rocky Mountain Construction, of Hayden. Construction began in April.

WhiteWater West Industries, in Richmond, British Columbia, designed the slide.

Silverwood was the first in North America to purchase it and have it built, said Nancy DiGiammarco, a spokeswoman for Silverwood.