It's just not summer without "Shark Week." And in 2007, the ultimate must-watch summertime television event is turning 20 - making it cable's longest running event.

Hosted by "Survivorman's" Les Stroud, "Shark Week's" 20th Anniversary will fill Discovery Channel's total day schedule from Sunday, July 29, through Saturday, August 4, from 9 a.m. to 3 a.m. (ET/PT) each day - adding up to over 130 hours of shark programs devoted to the behavior of one of the most mysterious and majestic creatures on the planet. Also to be featured is a programmed-by-you Viewer's Choice hour at 8 PM, and eight all-new primetime specials at 9 PM.

For the past two decades, "Shark Week" has intrigued, educated and enthralled viewers. Who can forget the footage of huge great whites bursting out of the water, launching 10 feet into the air, shown for the very first time on "Shark Week"? Or the first-ever 3-D shark program, with sharks big, small and unusual seeming to swim right out of television screens and into living rooms across the nation? And every year since its inception in 1988, "Shark Week" has partnered with the world's most renowned shark scientists and experienced underwater cinematographers to bring viewers the latest information about the ocean's top predator.

Les Stroud, outdoor adventurer, instructor in survival and host of "Survivorman" on Discovery Channel, will host "Shark Week" this year. During premiere program breaks in the 9 PM hour, he will offer practical and potentially lifesaving tips that show viewers the best techniques for surviving an encounter with a shark. In addition to providing critical safety and awareness knowledge, Stroud explains that, while sharks are incredibly efficient predators, they are not mindless killing machines. For a safe coexistence with sharks, we must acknowledge that ultimately the waters are the shark's domain. Stroud will also host one premiere special, "Shark Feeding Frenzy" (July 31, 9-10 PM), which will examine the feeding habits of sharks.

The 9 PM premiere hour will kick off on Sunday, July 29 with the two-hour special "Ocean of Fear: Worst Shark Attack Ever," which is narrated by Richard Dreyfuss and tells the gripping real-life story of the worst shark attack ever recorded - after the sinking of the U.S.S. Indianapolis in 1945.

Additional "Shark Week" premieres include "Deadly Stripes: Tiger Sharks" (July 30, 9-10 PM); "Top 5 Eaten Alive" (July 30, 10-11 PM); "Shark Feeding Frenzy" (July 31, 9-10 PM); "Perfect Predators" (August 1, 9-11 PM); "Shark Tribe (August 2, 9-10 PM); "Sharks: A Family Affair" (August 3, 9-10 PM); and "Sharkman" (August 4, 9-11 PM). All times ET/PT.

In another "Shark Week" first, viewers are being given the opportunity to help program television's most anticipated summer event. Via the "Best of Shark Week Poll" at Discovery.com/sharkweek, viewers can watch clips from 10 of the highest-rated and most talked-about "Shark Week" programs of all time - and vote for their favorites. Voting continues through July 1, with the top voted shows airing in "Shark Week's" 8 PM hour.

Among Discovery.com's exciting online "Shark Week" features: a game based on real-world tracking of live sharks in the wild, a video mixer that allows users to create their own mini-"Shark Week" documentaries, exclusive behind-the-scenes video, information about sharks and more.