Go find the Rusty Crate in the Sea of Atlantis. Defeat the ghost that comes out of the chest to get the important item, then report to Muto.

Show Quest Info

Introduction

Sibb is familiar with the sea nearby, so Muto trusted him to assist you in finding the Rusty Crate. It's said the chest belonged to a fleet with an eagle flag. Muto learned this information from Warren's secret record.

NPC Dialog

The Rusty Crate seems to be very important to
Muto since he has repeatedly asked me to help you
find it. However, there are many Rusty Crates in
this area, so I think well just have to try our luck. I
have only one hint for you: Its said the chest
belonged to a fleet with an eagle flag, so there will
probably be an image of an eagle on the chest.

Quest Completion

Great, you've found the Rusty Crate! So did you get
this from the chest? Let me see...Wow, it's Divac's
expedition diary! I know Divac had a habit of
recording everything he encountered in his diary. I
thought Divac's diary must have sunk to the
bottom of the sea along with the fleet, I wasn't
expecting to see it today! This clue is the key, with
it we will know why Divac's fleet was wrecked and it
will reveal the secret of Golden Island!