You were on a cruise from New Zealand to Australia. Suddenly, there is a loud grating sound and you peer over the side to see a coral reef tearing a large hole in the side of the cruise ship. Seeing the mess with the lifeboats, you dive over the side, swim for the nearest island, and pass out.
When you awaken, you are alone and a large, water-tight box has washed ashore with you. You remember seeing a box for the satellite phone on the ship that looks exactly like this one. However, only the captain knew the secret codes to get in. More items wash ashore and you realize he had written down clues to help him remember.
There is a small hole on the side of the box and you estimate the box will be filled with water and sand in 45 minutes, rendering your one hope for rescue useless.