Physics of Windsurfing

This is fabulous!

This is a commendable illustration of the "uniqueness" of windsurfing control. Especially, how the pressure under the foot is involved. You should have furthermore shown how the foot actually executes "turning the board" during a slow tacking turn. The sail stays in position, while the foot actually forces rotation of the board. As a windsurfer, in slow wind conditions I often execute a quick 270 deg jibe turn. The sail/boom/mast acts as an "anchor" while my feet is "muscling" the turning force against the board. Many beginning windsurfers don't understand this and have trouble executing turns, because they think the wind does all the work(like a sailboat).

Good as far as it goes. I don't normally comment on these things but I feel some of the inaccuracies are so glaring I have to say something. Let’s start with the positives. The graphics are great and so is your systematic explanation (although flawed in some places). For a beginner this introduces some difficult concepts in an understandable way but starts to unravel when you talk about lift and steering. If you put the correct numbers in the wing simulator accounting for apparent wind angle and the correct sheeting angle for the speed of the apparent wind then you get a very different result. This is how you explain the fact that at full speed on a broad reach, a speed sailor is almost fully sheeted in. In your model this could never happen because you could never generate an apparent wind sufficiently strong at such an angel. Then we get on to steering which deserves its own video. Pressure on your feet is irrelevant to steering with the sail from a physics point of view. Your feet are only transferring the force from the sail. This is then complicated by foot steering which is where you use the board moving over the water to steer like you would a surf board. Both of these are effected by the speed of the board and the relationship between the Center of Effort (CE) of the sail and the Center of Lateral Resistance (CLR) of the board. As a beginner foot steering is all but irrelevant. As an intermediate/ advanced sailor, sail and foot steering is used constantly in combination. At high speeds, the setup of the board and sail also become more important as you can tune the relationship between the CE and CLR to give a setup for different things. Hope this helps some one.

Nice job! While I was at high school my uncle (physicists) was explaining to me sailings physics on a notebook. It’s nice to see a simulator!

It is well explained but very simplified as the sail isn't really being pushed by the wind but rather pulled by the low pressure created on the downwind side of the sail.

Looks like a lot of effort to design it in 3D. Thanks for explaining with engineers eyes😉🙌 great stuff

Well done! Thanks so much for taking the time to make this!

Great video! I have always had my doubts about "lift" in windsurfing. This cleared it up! Thanks a lot for putting in the work to make this!

Great graphics, really cool to see the analogies we use as instructors shown this way; que ball, and apparent wind for example. Can’t imagine it’s as quick to make somethings like this as it is for me when I jump on a board with a few cameras and a mic. 😉

It's good to visualize these mechanics for an even better and faster understanding of windsurfing.

Fantastic presentation, thank you. The steering section is the best explanation I've seen for beginners, indeed its what I've been teaching for years rather than the 'lateral resistance' explanation I've heard some people give. And the physics stuff is fantastic. What I'd like to see next is 'how foils work' and I'd happily collaborate with you on this! Thanks, Guy

This is an incredible video. So much work went into this. Great job 👏🏻 incredible illustrations. Love it

This was really helpful! I didn't really understand what apparent wind was before this, or that it could change your no-sail zone. Thank you!

thanks so much for the time you put into this - very helpful

Excellent ! Finally a video that explains this simply and clearly from first principles !

We need more videos like this!

Just great. Thank you very much for the hight quality contribution

Great presentation and detail. Just one thing... if the board is displacing water, what you say about steering is true. When lift from the fin and speed of the board across the surface of the water causes it to plane (not displace) it steers more like a skateboard, responding to rail to rail pressure. In addition the rig/sail is tilted towards the back of the board as the wetted area of the board decreases due to upward lift from the fin, so the centre of effort in the rig moves back as the board accelerates. This is why the windsurfer starts by standing just behind the mast, but later moves to the back of the board into the foot straps.

great video! Im waiting for 'physics of windfoils' that will be interesting too! cheers

Very clear, very precise, very informative, great job, thank you so much for your contribution, itmakes me feel suddunly a bit less dummy !!!