What Happens To A Water Bottle Underwater?

The experiment begins by filling a water bottle with air before taking it underwater. As the bottle descends, the air inside compresses, causing the bottle to compress as well.

The diver takes the bottle to a depth of 25 meters (82 feet), opens it, and fills it with air. Since the bottle is a closed container, filling it with air at this depth and sealing it should cause it to expand on the way back up.

This phenomenon is compared to how a BCD behaves as a diver ascends, requiring air to be vented. The video shows the bottle expanding significantly at 14 meters and again at 6 meters due to the pressure change.

The final clip shows the bottle right before reaching the surface, appearing very rigid from the expanded air inside. The video concludes by demonstrating the expanded bottle once opened above water.