Hydraulics and Fluid Mechanics


The object is to design and build a device that can hold an object above the specified heights, while remaining in contact with only water. The challenge will be moving the device and object over the determined course based on the specific gravity of the object. There will be a poster presentation and race portion for the event.


  • One team per school can compete. Each team may consist of up to four students.
  • Students will design a device to hold an object above a minimum height of 4 feet. This can be achieved by a container of water, or via water jets.
  • Teams will race with the device and the object over a course which varies based upon specific gravity. The location in which the race will take place will be flat, i.e. Parking Deck, Football Stadium or another suitable location.
  • During the race the object must stay in contact with only water at all times.
  • The device to be constructed may have wheels, however to move the device there cannot be any type of propulsion. The only way the device will be allowed to move across the race distance, is through physical effort by 1 or more members of the team.
  • If a vessel is used to suspend the object, then its bottom must always stay below a maximum height of 3 feet.
  • Objects must have a volume between a minimum volume of 12 cubic inches (roughly a baseball), and a maximum of 20 cubic inches (roughly a softball).
  • The object must be negatively buoyant, with a minimum specific gravity of 1.05.
  • There is no restriction on the shape of the object.
  • The race distance will be between 100 and 400 yards, based upon the measured specific gravity of the object. Objects with higher density will be awarded with a shorter race distance. Below is a table to show race distances based on specific gravity.
Specific Gravity Distance to be Travelled
1.05 - 1.2 400 yd.
1.21 - 1.4 300 yd.
1.41 - 1.6 200 yd.
s.g. > 1.6 100 yd.
  • The race will include staggered starting locations and a common finish line.
  • Teams finish the race when their object reaches the finish line.
  • The solution must be water based combined with edible ingredients.
  • There will be an informal poster presentation prior to the race explaining to the judges your design process and the function of your device. The poster should be 36” x 48” in size and at minimum include a picture of your device, the ingredients used in the solution, and the function of your device. The presentation should be approximately 5 minutes in length. Judges will be able to ask questions after the presentation.


Teams will be graded on the quality of their presentation (A = 1, A-/B+ = 2, B = 3, C = 4) and according to the placing at the race (first place = 1, 2nd place = 2, 3rd place = 3, etc.).  Teams will then be ranked according to their cumulative score (presentation + race).  The winner will be the team with the lowest overall score. Judges on the course will ensure that the object and the device meet the height limits and will stop teams mid-race until which time the height limits are met.