Plastic Egg Submarines

When my son was preschool age we had fun doing alphabet activities using vehicles.  For the letter “S” we did submarines, which meant we HAD to have some water play time.  Making egg submarines with plastic Easter eggs was a huge hit. (Learning with plastic eggs is so fun!)

This plastic egg submarine activity was inspired by this Sink the Easter Egg activity.

Materials Needed:

• Plastic Eggs
• Pom poms, beads, and other small items that fit in the eggs
• Coins
• Clear Tape (optional)
• Game Dice (1-2)

The object of this activity is to figure out how to make your plastic egg sink like a submarine.  (In the fall try our pumpkin sink or float activity.) I had a collection of beads, pom-poms, pennies and quarters on hand to use to help sink our plastic egg submarines.

We used 4 eggs and rolled a game die to see how many of each object would go into each egg.  Then I asked the preschooler to guess whether or not the submarine would sink or float, and we set each egg in the water.  (If your eggs have holes in the ends, you will want to use a bit of clear tape to cover them.)

We soon discovered that the pom-pom egg floated at the very top of the water.  The one with a few beads was also at the top.  The submarines with pennies and quarters sank part way.

How could we get the eggs to sink? 

We tried completely filling one egg with the pom-poms, one with beads, one with pennies, and one with quarters.

Before placing our submarines into the water this time, we put a few of each item (pom-pom, quarter, etc.) into the water.  The preschooler noticed that the pom-pom and some of the beads floated, while the coins sank right away. We talked briefly about why that may be.

Then we tried our newly filled eggs.

The preschooler was very happy to see the penny and quarter-filled egg submarines sank to the bottom.

When he realized the bead and pom-pom ones were still not sinking, we talked about how the plastic eggs still had air in them, helping them float.   Then we tried filling those spaces with water — success!  The plastic egg subs all sank.  

The preschooler continued filling eggs, watching them sink or float while I prepared lunch.  He asked to continue the play after lunch, too.

Plastic egg submarines are a simple sink and float science activity that your preschooler will love.  

Other STEM activities:

• Design a Boat That Floats
• Create Your Own Cardboard Tube Marble Run
• DIY Geoboard