Factual error: The storm that causes the plane to crash has supposedly also created a tsunami, which is headed for the island that the main characters are on. They claim to have "four or five" hours until it arrives. First of all, tsunamis aren't caused by storms. Additionally, when the "tsunami" is shown out at sea, it appears as a giant wave that overturns a cruise ship. In reality, tsunamis don't crest like that until they get close to land. Out at sea, a tsunami can pass right under a ship and the passengers would never know it.
Factual error: When the good guys finally find Columbus' treasure, it's in a wooden chest sitting outside. It seems unlikely that it would have survived 500 years outdoors. Even if no one had discovered it, the wood would have disintegrated long ago.