Story Quests/World 3: Endless Blue/Ship? Wrecked.
The crew manages to fight off the Kraken, but the damage to the keel has been done- the ship sinks to the bottom of the sea. When Light and the others come to, they find themselves somehow able to breathe in a world underwater.
Marina: Uh-oh. The keel's broken, you guys.
Alk: What does that mean, exactly?
Marina: The ship's gonna sink.
Alk: Seriously?!
Everyone: AAAAAAHHHHH!
Alk: Ngh...
Alk: Wait, what?!
Alk: G-guys, wake up!
Nimbus: Five more minutes...
Nimbus: ...! Wait... What the hell's going on here?!
Light: W-we're underwater?! I-I don't know how to swim! BLURGHARGH!
Stella: Relax, Light. We can breathe.
Light: Y-you... You're right.
Light: But the question remains... How is this happening?
Alk: Do you guys feel any different?
Light: No... And that is what's strange.
Stella: This appears to the be the ocean floor. I surmise that we sank here after being attacked.
Nimbus: ...Hey. Where's Marina?
Alk: And the rest of the crew, for that matter!
Stella: We should have been together when the ship sank.
Light: Perhaps the tides carried them somewhere else. How long have we been down here?
Light: We have many unanswered questions. Let's begin searching for answers.