Ocean Depths.

Okinawa has the Okinawan Trough to the west of the main island of Okinawa.  The trough drops to a depth of around 2000 metres. However just to the east of Okinawa is the Ryukyu Trench which averages around 7000 metres and at the deepest point is almost 7500 metres. They have a display of what happens to a polystyrene cup at various depths. The crumpled metal object on the right hand side was a metal baseball bat.