top of page


Learning Intention:


To become familiar with the parts of a sailboat and understand how they make it work. To experiment with a variety of materials to create a boat and use problem solving strategies to change it to perform better.

Parts of a boat? Thanks to USS for the video



Most sailboats consist of eight main parts: mainsail, jib, hull, mast, boom, tiller, rudder and keel.  


The sail harnesses the wind to move a boat forward.  A large mainsail is supported by a vertical mast and a horizontal boom.  A jib is a smaller sail that adds more power.

To go forward, a sailor turns the boat so that it’s at an angle to the wind and as the wind fills the sail, it creates a shape called an aerofoil – that means it’s also like a wing. By moving the sails  they can work with the wind to go in the direction they want. Quite often this has to be in a zigzag path to catch the wind in the right way to keep the aerofoil shape on the sail.  

The hull is the body of the boat and sailboats can have more than one. The front of the hull is called the bow and the back is the stern.  Multihull boats are more stable.  Their hulls are narrow and spread apart so they are harder to tip over.

The keel is a heavy blade on the bottom of the hull that stops the boat from moving sideways.  Small sailboats have a centreboard, which is a keel that can be raised and lowered.

Activity:  Build a sailboat with a hull, sail and mast and keel.


Materials:  Use recycled materials where you can.

A list of suggestions below for the boat:


  • Aluminum foil                                  

  • Foam sheets            

  • Sponges

  • Scrap paper and card                    

  • Plastic wrap            

  • Wood scraps or branches

  • Scrap fabrics                        

  • Rubber bands          

  • Egg cartons

  • Styrofoam                                        

  • Straws                      

  • Cardboard tubes

  • Twist ties                                          

  • Wax paper                

  • Cups                        

  • Dowel                                                

  • String                        

  • Old pens

  • Plastic lids and containers            

  • Metal washers        

  • Skewers

  • Plastic bags                                    

  • Tissue paper                                                            

  • Toothpicks                                              

  • Pool noodles


Other Materials:

  • Scissors

  • Rulers

  • Hot glue gun

  • Tape

  • Battery operated fan for testing

  • Large plastic storage container - used to test the boats




Work in groups for this activity.  Focus on just four parts of the sailboat: The hull, the mainsail, the mast and the keel.


Design a sailboat to float and to sail from one point to another.  Which materials make the best sailboats?  Test in a tub of water using a battery operated fan, a paper fan or the wind.


You should think about size, weight and the shape of the hull, keel and  sail. (You could use the sail from the sail power activity.)


While testing, observe which floats the best. Why?  What shape performs the best?  Which is the most stable?  Does size matter?  Are the boats that are performing the best made of similar materials? What would they change if you were to start again with their design?




Sail, hēra.


Buoyancy, puhautanga - The ability of something to float in a liquid.


Displacement - The moving of something from its place.


Life jacket, kahu kautere.


Upwind - Sailing in the opposite direction in which the wind is blowing.

Downwind - Sailing in the direction in which the wind is blowing.


Force - A push or pull on an object.

Windward - The side of a boat that is facing the wind.


Leeward - The side of the boat that is sheltered from the wind.


Luff - The front or the leading edge of a sail.


Leech - The back edge of a sail.

Foot (of a sail) - The bottom edge of the sail.


Woolies - Or tell-tales are the strips of ribbon or wool on the side of a sail.


Waka - A traditional Māori canoe.

Kevlar - A very strong synthetic fibre used to make sails and bullet proof vests.


Carbon fibre - A very strong lightweight synthetic fibre used for high performance products like sails, boats and aeroplanes.

bottom of page