Sink or Float Preschool Activity: Will the Boat Sink?

Do you want a sink or float preschool activity that’s hands-on and literature-based? Try this simple STEM lesson inspired by What This Story Needs is a Pig in a Wig by Emma Virján. It’s an ideal way to encourage exploration and introduce science thinking while connecting with a fun rhyming story.

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First a Story: Connect Literacy to Science

Start by reading What This Story Needs is a Pig in a Wig. In this story, a pig (in a gorgeous red wig) sets sail in a boat—but things quickly get crowded as a dog, frog, goat, skunk, and even an elephant join the ride! Eventually, the pig decides to get a bigger boat.

It’s a silly story that leads naturally to a big science question:
Can a boat really float with so many animals on board?

Demonstrate the Sink or Float Preschool Activity

After the reading the book, introduce your STEM activity with a simple teacher-led demonstration. This helps children understand the process before they try it on their own.

Demonstration Materials

• A plastic lid (from a yogurt or margarine container)
• A shallow bowl or bin of water
• A small plastic pig (I found these small bathtub toy pigs on Amazon. I pulled out the squeakers to keep the kids focused on the experiment instead of the noise.)
• Optional: chart or whiteboard to record predictions

Steps to Model:

• First, Float the Boat
  Place the lid in the water and ask, “Does our boat float?”
• Next, Add the Pig
  Say, “Let’s give the pig a ride on the boat!” Gently place the pig on the lid. Ask, “What do you think will happen?”
• Then, Add More Animals
  Once the pig is balanced on the boat add animals one by one. Count aloud: “How many can the boat hold before it sinks?”

Encourage students to make predictions and observations during the demonstration. Then invite them to try the activity at hands-on stations.

Explore at Stations: How Many Animals Will Sink the Boat?

Station Materials

Set up small sink or float exploration stations around the room. Each tray should include:

• A shallow container of water
• A plastic lid “boat”
• One plastic pig (We used these small bath toy pigs)
• Up to 9 additional small animals or counting bears
• A towel or tray to catch spills
• Optional: a printable recording sheet

Children begin by balancing the pig on the floating lid. Once they succeed, they can test how many more animals the boat can carry before it sinks.

Note: For two-year-olds, I tape the container of water to the tray to discourage them from dumping the water.

Use Guiding Questions as They Explore

Support science thinking with open-ended questions like:

• “What do you think will happen if you add another animal?”
• “How many animals does your boat hold before it tips or sinks?”
• “What happens if you try a different lid or shape?”

Try Again with a Bigger Boat!

Just like in the story, the pig eventually needs a bigger boat. Invite children to test a second design using different materials. You may want to have a station set up with a larger pan of water to fit a bigger boat.

Alternative Boat Ideas:

• Plastic takeout container lids (wider and flatter)
• Squares of aluminum foil (let children shape their own boats)
• Half of a small styrofoam takeout container

Encourage comparisons:

• “Does this boat hold more animals?”
• “Which boat floats better?”
• “What did you change on your boat so that it can hold more animal?

Printable Recording Sheets to Extend Learning:

To help children track their results, provide one of the simple printables from the free resource in my subscriber library:

1. Sink or Float – Lid Test Sheet
   • “Draw the animals on the lid.”
   • “Add a dot or stick for each animal that you place on the lid before is sank.”
2. Sink or Float – Design Your Own Boat
   • “Draw the boat you designed.”
   • “Fill in the circles to show how many animals fit on this boat.”
3. Cut and Paste STEM Story Extension
   • This is an empty boat picture with animals to cut and glue aboard.

These are available in my free subscriber library—you’ll get a lesson plan and three printables.

Finally, Wrap It Up with Creativity

Close the activity with reflection and creativity:

• Let kids draw a picture of their boat and the animals it carried
• Make a mural: Have students paste or draw animals on a class “boat”
• Create a bar graph together: “Which boat held the most animals?”

Why This Sink or Float Preschool Activity Works

This activity supports key early learning goals:

• Making predictions
• Observing and comparing results
• Counting and graphing
• Learning through play and exploration

It also builds a strong connection between literacy and STEM, making learning memorable.

Take It Further

Here are a few ways to extend the fun:

• Build and test boats with different shapes or materials
• Let students invent their own silly boat story!
• Set up the activity in the sensory bin using different sizes of lids.
• To add a fine motor element, place tongs in the sensory bin for students to pick up and place the animals on the boats.

Ready to Try It?

This sink or float preschool activity is easy to prep, engaging for kids, and filled with learning. Want printable tools to make it even easier?
Grab the free resource in my library!

Note: I do not receive any commission from the Amazon links. I just want to share what has worked for me.