How Does Sound Travel Underwater

First, how do you think sound traveled to our ears? "What is between us that we can't see? Air! Sound waves travel slowly through air. What we hear most of the time is sound moving through a gas. To demonstrate clink two butter knives together and listen. What would happen if we clinked the same knives under the water? Submerge the knives to make the sound again in a bucket full of water. Cut the bottom off of a large plastic water bottle. Once submerged in water use it to listen under the surface (as you can see in title photo). Take turns clinking the knives and listening. 

The result is a louder, better, and clearer sound! Sound waves travel faster through water. Discuss what animals hear underwater. You could also mention that sound also travels quickly through solids. You can put your ear to a table or wall and knock to demonstrate the vibrations of sound passing through a solid object.