This week we found out how a submarine manages to float and sink.  We found out that it has tanks called ballast tanks.  It fills these tanks with water when it wants to dive under the water.  It empties these tanks and the air in the tanks let the submarine go back up to the surface.  We found out that a submarine has a propeller to move it forward through the water and fins on the side called hydroplanes to help it turn from side to side.  The people in a submarine have to use a periscope to see out and they use computers to help them find out where they are going.

They are used to dive deep in the ocean to study sea creatures and wrecks.

We wrote our explanations of how a submarine works.

Our next challenge is to use our construction to try to build a submarine.