The Lifeboat Clique by Kathy Park

When an earthquake and tsunami hit an illegal high school party in Malibu, it decimates the house and the attendees. Later, a few kids cling to a chunk of debris floating in the ocean - including one very unpopular girl. What's worse: being lost at sea, or being shunned by the cool kids WHILE you're lost at sea?

Denver and Abigail used to be best friends, but now Abigail's popular and Denver is a pariah (we don't find out why until later, but it's easy to see it's the typical high school falling out). While the group drifts at sea, it's Denver's practical skills that allow their survival, but even that isn't enough to win over Abigail. It's hard to ignore someone in such a small space and under such harsh conditions, but Abigail's sure making the most of it.

It's a good book, and it moves quickly despite the harrowing situation. There's a bit of a "moral" but it's not too preachy. The characters are recognizable as the typical high school clique but still have depth and interest.