Moving on Water

In this lesson, students will learn about how and why things float, and design and test sails.

0-30 min
Reception-Year 1


  • Review this lesson plan and choose what you need from the Teacher Support box.

  • If necessary, pre-teach these related vocabulary words: characteristics, features, sink, float, sail.

  • Consider the abilities and backgrounds of all your students and decide when and how to introduce and differentiate lesson content, activities, or concepts.

  • The Science Behind the Play: Objects that float are positively buoyant and there are several reasons why they float.

    • Objects that are less dense than water will float. Density refers to how much mass an object has relative to its size. For example, most rocks sink in water because they are denser than water.
    • The structure of an object also affects how water moves around the object's surface. For example, the structure of a boat creates a large surface for water to push against. However, if too much weight is added to a boat, it will sink beneath the water.
    • Some objects are neutrally buoyant. This means that they sink beneath the water’s surface, but they do not sink all the way to the bottom. This happens when an object’s density is the same as the density of the water it is in.


  • Tell the students that you will be playing a game called sink or float.

  • Explain that they will have 10 seconds to choose an item from the room and bring it to you, then set a timer or count to 10 while the students choose their items.

  • As a group, sort the items into a “sink” pile and a “float” pile, then test the items in a container of water to see if the predictions were correct.

  • Ask the students to look at the elements in the STEAM Park set and select some they believe will float, then test the items to see if their predictions were correct.

  • Consider recording the results of the tests on one of the printable graphs.

  • You might also consider asking questions like:

    • What are the characteristics or features of objects that float?
    • What are the characteristics or features of objects that sink?
    • What would happen if you place an object that sinks on top of an object that floats?
  • Tell the students that you are going to read the beginning of a story about a group of people who are preparing STEAM Park for its daily visitors. You can show them the inspiration photo or use the figures to act out the story.

  • Read the following story aloud:

Arty, Teresa, Parker, and Ms. Engels were at STEAM Park early in the morning.

Parker, the park manager, said, “I have four boats that park visitors could ride in. However, we need to find a way to make them move across the water.”

“Do you have some materials we can use to make some sails?” Teresa asked.

“Great idea! What about markers to make colorful designs?” Arty asked.

“Yes, I have a lot of supplies we could use! Let’s get started!” Parker said.


  • Encourage the students to think of ways to make boats and other floating objects move across the water.

  • Show the students the inspiration photo for the “Moving on Water” lesson.

  • Give the students art supplies and printouts of the sail template, then ask them to create their own sails for the boats and test them.

  • Consider asking questions like:

  • How can you make the boats move without touching them?

  • What could we use to make “wind?”

  • What would happen if you placed objects in the boat?

  • What would happen if you dropped objects in the water around the boat?

Tip: Laminating the sails will make them stiffer and more durable, and using the boats without the figures makes them more stable.


  • Prompt a discussion about which sails work the best and why by asking the students to explain what happens when they use a sail to move a boat.

  • Consider asking questions like:

    • Which sail makes the boat move faster?
    • What would happen if you moved the sail to a different position?
    • How far can you make the boat travel when you blow one breath of air into the sail?


  • Play a game using the boats by creating an obstacle course, a relay, or a race.

  • Place the balls and muffin cup elements in the water and tell the students to navigate around or between the obstacles.

  • Another idea is to create teams and tell the students to create waves to try to sink the opposing team’s boat.

Did you notice?

  • Ask guiding questions to elicit students’ thinking and their decisions while ideating and building: What do you wonder about…? What do you notice…?

Observation Checklist

  • Review the learning objectives and success criteria addressed in this lesson (Teacher Support box).

  • Share specific student responses and behaviors at different levels of mastery.

  • Use the following checklist to observe students’ progress:

    • Their investigation plan includes a way to observe and collect the data about which sails worked to make the boat move across the water.
    • Students can describe measurable attributes of the boats such as the length of the boat or the height of the sail.
    • Based on their observations of the boats’ movement across the water and their analysis of the data they collected, students can describe which sails were more successful and why.

Teacher Support

Students will:
Experiment with the idea of sinking or floating
Learn which sail design works best for the boats in the set
Record data using graphs

STEAM Park set

Hole punch
Colored pencils or markers
A large container or sink filled with water, straws and fans (optional)
Lamination machine (recommended)

NGSS K-2-ETS1-3. Analyze data from tests of two objects designed to solve the same problem to compare the strengths and weaknesses of how each performs.

CCSS.MATH.CONTENT.K.MD.A.1 Describe measurable attributes of objects, such as length or weight. Describe several measurable attributes of a single object.