Physics Underwater: Davy Jones' Flying Dutchman

Jack Sparrow is ready to face Davy Jones and his crew.

The saga of the "Pirates of the Caribbean" has, immediately, enjoyed a worldwide fame thanks to the talented group of actors presented by Gore Verbinski and the original storyline written by the producers. The various episodes describe the adventures of Orlando Bloom, Johnny Depp, Keira Knightley and Geoffrey Rush, committed to challenging fearsome creatures of the sea.

In the famous chapter "The Pirates of the Caribbean - Beyond the World's Borders", a peculiar super villain gets into trouble Captain Jack Sparrow and his fellows. His name is Davy Jones and he is the captain of a ghost ship called the Flying Dutchman; he has the power to trap the souls of battle prisoners on the ship and trap them in the wooden structure of the vessel. In many scenes, the Dutch emerges from the depths of the ocean, although not having any type of engine!

Davy Jones, captain of the Flying Dutchman, will be Jack Sparrow's enemy.

Let's analyze how Davy Jones's boat manages to do this.

When a body is placed into a fluid, it is subject to an upward force equal to the weight of the displaced fluid. This is the statement of Archimedes Principle and the relative thrust is called the Archimedes' thrust. This is the fundamental reason why some objects in water float and others sink (some are more dense than water, others not).

Fb is the thrust of Archimedes produced by the immersion of the body into the fluid. In this case, the body floats on the surface.

According to this principle, to allow a body to reach the surface of the water, the Archimedes thrust must be equal to the object's weight. To do this, it is necessary to decrease the object's average density. In the case of the Flying Dutchman, the ship's average density is lowered by introducing air into the vessel. This allows the boat to emerge from the depths of the oceans. Therefore, the Flying Dutchman should be equipped with tanks that can be filled (or emptied) with air and water. 

Davy Jones exploits Physics to surprise his opponents and throw them into the depths of the ocean. Jack will have to do his best to defeat this extravagant opponent.