Here are some boats I made. Can you spot someone having a sail?
You can make boats out of many things you have at home. You could try folding paper into the shape of a boat. You could use aluminium foil to bend and shape so that it floats.
Once you have some boats, try floating them on some water (or even when you are having a bath). How long did it float for? Was it able to carry any toys? Did you add a sail?