- You can basically use any materials to make the sail for the boat but do keep in mind that it needs to be light and well balanced with the size of the ice boats as the sail can flip the boat upside down if it is too heavy.
- I added the straw sails to the ice boats when they were partly frozen. You could alternatively use blu tac or plasticine at the bottom of the container when adding the water.
- This activity is great for encouraging countless science related discussions about ice and water, floating and sinking, liquid and solids. Exploring questions such as why do you think water expands when it is frozen? Why do you think ice floats on water?
- When water is frozen, it increases in volume or expands and decreases in density, which makes it much lighter than its liquid form. As water becomes colder and begins to freeze there is a change in the unique molecular structure of hydrogen and oxygen that allows it to float.
I am sure you all understand why I am mentioning this but I cannot stress this enough: please always supervise and watch children when playing with water!