Cardboard Boat Design Challenge
Grade 8 Science – Mr. Birt
Introduction:
Boats come in all sizes, shapes, and
kkkkk colors!
Some have trouble going the same
direction as others!
Have you ever wondered how a large
supertanker filled with oil can float?
Objects submerged in a fluid such as water appear to weigh less than they do when they are not in the water.
The liquid exerts a buoyant force on the object. Archimedes is credited with discovering that the buoyant
force on an object is equal to the weight of the displaced fluid. (He is said to have discovered this principle in
his bath while trying to think of a way to determine whether the king's new crown was gold or a fake. Legend
says that he ran naked through the streets shouting, "Eureka.") Archimedes Principle also applies to floating
objects. For our supertanker to float it must displace a volume of water equal to its weight. An object floats on
a liquid if its density is less than that of the fluid.
Objectives:
 To build a boat out of cardboard and tape capable of holding two people that can be launched and
paddled across a pool.
 To apply Archimedes' Principle to your design.
Materials:
 Only cardboard and tape may be used to construct the boat
 You may NOT use any other objects or material to contribute to the craft’s structural rigidity.
 You may only use packing tape that is up to 5 cm wide. Clear tape is cheapest. NO GLUE!
Design Criteria:
Boats will be subject to a technical inspection before the day of the race and must follow these guidelines. Any
boat not following these guidelines will be penalized (reduced mark) or disqualified.
1. Boats must be made from corrugated cardboard. The entire hull, superstructure, and seating must also
be made from corrugated cardboard.
2. No treated cardboard is allowed. Your cardboard must be brown! Treated cardboard looks like it has
been waxed. You may not use painted cardboard.
3. Commercial containers (large drums, bottles, or containers) cannot be used.
4. Styrofoam is not allowed for environmental reasons and entries will be disqualified if styrofoam is used.
5. NO rafts are allowed!
6. Your craft must at least carry 2 people.
7. Your group may design a craft for your entire group if you choose. But you need to consider the added
design challenge of making it strong enough structurally to carry the additional weight and withstand
the force of the displaced water.
8. The maximum length is 2 metres. Your boat must be narrow enough to fit through the doorway.
9. Swimming on a cardboard surfboard is not allowed. No appendages are allowed in the water.
10. The passengers of your boat may not be enclosed above the shoulders of the occupants. The people
must be visible while the boat is in the water.
11. Boats must be free of sharp edges, objects with pointed edges, or any other menace.
12. All occupants of a boat must wear a pfd.
13. All boats are to be propelled through the water by a paddle provided by the instructor.
14. Alternatively, you may construct a cardboard device (such as a paddle wheel) to power the vessel
15. To qualify as a finisher, both (or all) teammates must be in the boat at the end of the race.
Project Guidelines:
1. You will work in 3-4 member student teams.
2. This will be a two-week assignment. Our study of fluids coincides with the boat challenge.
3. All written documents are due Monday, December 14
4. Boats must be brought to the school for assessment Tuesday, December 15.
5. Due to space limitations at the school, most of the boat construction will be done at the home of one
of the group members.
6. The boats will be tested Thursday, December 17 at the University of Manitoba Swimming Pool.
Project Deadlines:
1. Documents due Monday, December 14
2. Boats must be brought to the school for assessment Tuesday, December 15.
3. Boats will be tested Thursday, December 17 at the University of Manitoba Swimming Pool.
Documents Required (35 marks):
1. Group Design Process Booklet (15 marks) - Shows the planning stages of your boat. (Provided
By teacher)
2. Group Work Log (5 marks) – Your group’s record of dates and times showing what each person
Did and when. (On looseleaf or typed)
3. Group Evaluation Form (5 marks) – A self assessment by the group of how well you worked
together and shared the work. (Form provided by teacher)
4. Individual Project Summary (10 marks) - It must include the following:
a) Effective Features – Describe at least three features of you boat that make it sturdy (strong),
buoyant (floatation), stable (untippable) and / or maneuverable (easy to paddle and turn).
(3 marks)
b) Improvements - A one paragraph description of two ways to improve your design and how the
improvements would help. Consider:
1) What part of your design seems weak or could cause problems?
2) What could you change or add to your design to make it more sturdy, more buoyant,
more stable, or more maneuverable?
3) How else could you change your design and why? (2 marks)
c) Archimedes Principle - It states that "The buoyant force on a body immersed in a fluid is equal
to the weight of the fluid displaced by that object." An object floats when its weight is equal to
the buoyant force. Write a one-paragraph description of how this principle applies to the
floatation of your boat. (Explain why it did or did not float.) (3 marks)
d) Buoyant Force - Describe how you could calculate the buoyant force exerted on your boat by
the water. What measurements would you take and how would you interpret them? (2 marks)
Boat Grading (15 marks):
1. Boat Construction (5 marks) - Finished boats will be graded according to the following:
a) Design of boat for strength, stability, and maneuverability (2 marks)
b) Attention to detail – cardboard cut and taped neatly (2 marks)
c) Portability – minimum size to carry two people or adequate size for more than two people
(1 mark)
2. Boat Performance (10 marks) - There will be a group grade for your boat’s performance. At least
two teammates must be in the boat. (10 points = 1 mark)
o Boat in water - 50 points
o Boat that just makes it off the starting line - 60 points.
o Any boat that successfully negotiates one-quarter of the pool's length - 70 points.
o Any boat that successfully negotiates one-half of the pool's length - 80 points.
o Any boat that successfully negotiates three-quarters of the pool's length - 90 points.
o Any boat that successfully negotiates the entire length of the pool - 100 points.