The official summary:
On vacation aboard a luxury cruise liner, Alvin, Simon, Theodore (voiced by Jesse McCartney), Brittany, Jeanette, and Eleanor are up to their usual antics, turning the ship into their personal playground, until they become ‘chip-wrecked’ on a desert island.
As David Seville (Jason Lee) frantically searches for his AWOL charges, the ‘Munks and Chipettes do what they do best – sing, dance and wreak havoc. But they’re in for a surprise when they embark on an island adventure with their new friend, a castaway who’s more than a match for The Chipmunks and The Chipettes.
While waiting for Dave to rescue them, they meet a modern day Robinson Crusoe who seems friendly enough until the ‘Munks inadvertently interfere with her real agenda – finding buried treasure.
The screenplay is by Jonathan Aibel & Glenn Berger, (Kung Fu Panda 1 & 2, Monsters vs Aliens, Alvin and the Chipmunks: The Squeakquel)
Alvin and the Chipmunks: Chip-Wrecked is scheduled for release on December 16th, 2011.