James Cameron has a special affinity for the ocean. He's directed films such as Titanic and The Abyss, not to mention his own deep-sea diving documentaries. So it shouldn't come as a huge surprise that his Avatar sequel will focus on underwater life in the oceans of the fictional moon of Pandora.
Story with video: http://movies.yahoo.com/feature/movie-talk-avatar-2-the-abyss.html
Story with video: http://movies.yahoo.com/feature/movie-talk-avatar-2-the-abyss.html