Set 12 years later after the previous film, upon discovering D.B.'s treasure, Jerry now with 3 kids, a girl born in 2004, a boy born in 2006, and a little boy born in 2010), Dano now a researcher and Tom now a billionaire, catch a flight from a trip in Hong Kong, but when the plane crashes into a deserted island, Jerry, Dano, Tom and their guide , Jermiah Tank must survive in a jungle of deadly attacks.
- Jerry Conlaine (Matthew Lillard)
- Dano Mott (Seth Green)
- Tom Marshall (Dax Shepard)
- Jermiah Tanks (Edi Gathiegi)
- Denise Conlaine (Bonnie Somerville) - Jerry's newfound wife
- Olson Conlaine (Dominac Scott Kay) - born in 2004
- Serena Conlaine (Ariel Winter) - born in 2006
- Jackie Conlaine (Logan Grove) - born in 2010
- Captain Clancy Ortago (Mickey Rourke) - the main antagonist, and captain of his crew of pirates to find and send Jerry, Dano and Tom into the mouths of sharks
- Malissa Ortago (Penelope Cruz) - Clancy's daughter, and Tom's love interest
- Wintergreen (Amanda Bynes) - a mermaid, who was once a adventurer who ended captured by Clancy, dressing her like a hula dancer to dance for him, and ended up getting drowned into the ocean, and turned into a mermaid
- Summer (Lindsay Lohan) - a mermaid, who was once a adventurer who ended captured by Clancy, dressing her like a hula dancer to dance for him, and ended up getting drowned into the ocean, and turned into a mermaid
- Maurice Hacket (Tony Todd) - Clancy's first mate!
- Bryce Troy (Bede Skinner) - Clancy's second Mate!