Season 4's Towering Flume of Doom
The Towering Flume of Doom is an obstacle, used as the first obstacle in the Summer Wipeout Zone of Season 4. It was interchanged with Chairborne (which was used as the first obstacle in the Spring Wipeout Zone, being interchanged with the Springshot (a modification of the Bobsled Blastoff from Winter Wipeout)) for the rest of the season.
It is a 7-story tall water slide where contestants open a door at the top and stand on a set of trapdoors. Then the door closes, and on the last second of the countdown, the trapdoors open from underneath them, dropping them down the slide and shooting them out and into the water.
It was replaced by Killer Luge in Winter Wipeout of the next season.
A similar obstacle named Drop Out later appeared as the first obstacle in the Wipeout Zone of Season 9 (TBS Season 2).