Windsurfing – a water sport invented in 1958. It is performed on a board with a sail. The sail both empowers the board and helps the board change directions. The sport is a combination of surfing and sailing.

Buoyancy arises from the fact that fluid pressure increases with depth and from the fact that the increased pressure is exerted in all directions (Pascal’s principle) so that there is an unbalanced upward force on the bottom of a submerged object.
What’s the problem?

Le Gouvello’s voyage across the Indian Ocean (video 4:31)
French windsurfer, explorer, and aquaculture vet Raphaela le Gouvello has crossed the Atlantic, Pacific, and Indian oceans on a specially designed sailboard that allowed her to sleep, eat, and send email.

An airbag system provided by the European Space Agency helped guard the craft from capsizing, satellite navigation helped her head in the right direction across isolated stretches of water, and solar cells generated electricity. This windsurfer is a great example of many types of engineers working together on a project. Technical details…

  • Ask – How is the windsurfer used? How long are the trips? What needs to be available for the trips? Most windsurfers are only out on the water for a few hours. For longer trips like this, the windsurfer includes a place to lie down and sleep, as well as a place to store food and gear.
  • Imagine – What do you need to have with you in the middle of the ocean? What emergencies should you be prepared for? A normal windsurfer can capsize pretty easily, which would be a big problem in the middle of the ocean. Finding a way to prevent capsizing was important. Using technology from the European Space Agency, the windsurfer design includes a system of airbags that provide buoyancy to keep it afloat. Additional design features keep it from tipping over. airbag – more…
  • Plan – How can the windsurfer stay on course? How can the windsurfer communicate with friends and family during the trip? Modern navigation systems using satellites allow the windsurfer to know exactly where she is and where she needs to head to reach her destination. These are light and portable, and can operate with batteries or electricity. Solar panels mounted on the deck generate electricity to power the navigation system, lights, a phone and a computer.
  • Create – How was the windsurfer constructed? The windsurfer is big enough to hold all the equipment and light enough to be powered by the windsurfer sail. Although this sail has been modified for the long distance, it is still very similar to the sail on a regular windsurfer.
  • Improve – What additions and improvements were made? Providing a place to sleep is a big improvement for a long ocean trip. Most windsurfers don’t need that.
Forces at work in Buoyancy

That’s engineering

Engineering ideas

  • fluids, buoyancy, displacement, fluid pressure, density, Pascal’s principle, Archimedes’ principle, hydraulic, structure, rigidity, stability, gravity, metacenter

Do it
Here are some challenges for you to work on…

  • Wetsuit for Paratriathaletes
  • Under pressure – Explore pressure under and above water. See how pressure changes as you change fluids, gravity, container shapes, and volume.
  • Watercraft – learn about the engineering design process and the physical principles of buoyancy and displacement by working together to build a boat out of straws and plastic wrap that can hold 25 pennies for at least 10 seconds before sinking.
  • Make a boat from a single index card. Discover ways to increase strength without adding any material. Perform testing, data recording, data analysis, compare results, explain results

Learn more…

  • Raphaëla Le Gouvello – story about her ocean crossings and her windsurfer
  • Airbag technology – In 2003, extreme sports adventurer Raphaëla Le Gouvello is about to windsurf 8000 km across the Pacific Ocean – from Peru to Tahiti in 80 days. Her board incorporates a new ‘anti-capsize’ airbag system, the first result of an ESA technology transfer initiative to improve safety for small boats at sea.
  • Pascal’s principle – overview of Pascal’s principle and Fluids concepts