Dry dock vessels can sink and float

Image

Image: U.S. Navy, YouTube

Right under the Coronado Bridge is California's largest floating drydock. This vessel, christened Pride of California, purposefully floods itself and sinks low enough so a ship can sail inside. The dry dock can then resurface, bringing the ship inside it out of the water for repairs.

How can a vessel sink and float on command? What causes a vessel to float? Why do some objects sink and some float?

Resources:

YouTube: USS Montgomery Enters Drydock

Type
Phenomena
Subject
Physics

More Activities & Resources:

How can fire be used to mitigate wildfires?
Phenomena
In March 2016, surveyors found fossilized whale bones and shells
Phenomena
Trackers on great white sharks in the Pacific reveal that sharks gather in a remote location
Phenomena

The Fleet Science Center invites you to connect to the power of science through FLEETtv!