Hi,

Ever since I started parawinging, I've been trying to find the perfect balance between board size and foil size. At my local spots, it's mostly open ocean waves. My goal is to glide as far as possible and play on the waves without relying on power from a wing or parawing.

With a wing, my go-to setup has been the North dw820/s142 foil (aspect ratio 13) paired with a 65L board. For reference, I weigh 95 kg. The waves at my local spot rarely exceed chest height, but are often around hip height.

For parawinging, I bought the North Midi 96L board and paired it with the dw1100/s192 foil (aspect ratio 12). This setup makes it easy to get up on foil and glide for long distances even in waves as small as 30-50 cm. The board and foil feel well matched in terms of turning radius, pitch control, and pumping. This setup covers all my parawing needs in winds below 20-25 knots, and it also works great with a 4.2 m2 wing for light wind wingfoiling down to around 10 knots.

The challenge arises when the wind exceeds 25 knots and the waves become too fast for the 1100/192 setup. I tried the 820/142 foil with the 96L board in 32-35 knots of wind and felt I had significantly less glide compared to using the same foil with the 65L board. I suspect this is due to the larger board causing delays in input to the foil, making it harder to make precise adjustments. The 96L board also felt a bit oversized in such strong wind.

Based on these experiences, I've developed the following theories:

1. With a larger midlength board, it doesn't make sense to pair it with a highly playful foil, since the board's turning radius limits how tight you can turn. It's better to choose a foil that matches the board's characteristics and prioritize glide/aspect ratio accordingly.

2. An oversized board relative to the foil causes input delays to the foil, resulting in reduced responsiveness, lift, and glide compared to using the same foil on a smaller board - and going too small on the foil doesn't necessarily make it more playful either, since you start losing glide and hit diminishing returns in performance. Of course, skill plays a part here, but my guess is that you at some point end up fighting against physics.

So I have a couple of questions:

1. In my case, would you recommend adding an 80L midlength board to my quiver? Or trying the same 96L board with a medium sized foil, like the North DW900? I'll probably end up getting both anyway. I feel I want to be on a little bit faster foil more often, but since the parawing doesn't give as much lift as a wing, I am afraid I won't be able to use my 820/142 setup as much as I want to.

2. Has anyone come up with any rules of thumb for the relationship between body weight, board size, foil, and stab for parawinging?

For example, in winds under 25 knots:
Board volume in liters = body weight
Front wing area in cm2= body weight x 11.5
Stabilizer area in cm2 = body weight x 1.7

It would be helpful to have a way to compare foil setups between riders - like a simple ratio based on body weight - so it's easier to see how someone else's gear might work for you.

I understand wave size, local conditions, riding style and skill plays a big role and that it's hard to give a definitive answer, but I'd love to hear some theories.

Great post!

1. In my case, would you recommend adding an 80L midlength board to my quiver? Or trying the same 96L board with a medium sized foil, like the North DW900? I'll probably end up getting both anyway. I feel I want to be on a little bit faster foil more often, but since the parawing doesn't give as much lift as a wing, I am afraid I won't be able to use my 820/142 setup as much as I want to.

When you start racking your brain on ideas like you have in this post every detail matters. 65l vs 80l vs 96l means very little to me. I've never found any correlation between volume and flight performance. Volume changes weight, length, width, thickness and those details tangibly change performance.

The way I view board dims impacting performance:
Length = pitch stability. If you want to offset this you can use a shorter fuse on your 820.
Width = roll stability. Changing your stance can help give you more leverage over a wider board to resist that stability.
Thickness = impacts on pitch, roll, and overall inertia. A shorter mast will offset this.
Weight = pumping and inertia influence. Nothing you can do to change this.
Volume = impacts takeoff and foil/sail selection.

2. Has anyone come up with any rules of thumb for the relationship between body weight, board size, foil, and stab for parawinging?

For example, in winds under 25 knots:
Board volume in liters = body weight
Front wing area in cm2= body weight x 11.5
Stabilizer area in cm2 = body weight x 1.7

I like the idea but I haven't isolated any equations here because, like you said, everything is so design, condition, and style dependent. However, this is why it's always so important to share all the details. Once you gather enough data patterns appear and you can develop something that has some general guidelines.

MidAtlanticFoil said..
It would be cool to make a google sheet with parameters to share with people, as this could offer a lot of guidance to new PW'ers.

Good idea. I've set up a simple survey. Not sure how easy it will be to get people to respond, but here's the link to the form:

docs.go [delete me] ogle.com/forms/d/e/1FAIpQLSeWx1U7OjsXxK3aTlOSJA7YM-9u5otbI-wpUi4TtC61D2PO_A/viewform?usp=dialog

I've also included a link to the Google Sheets document with the results so that anyone interested can access it and do their own analysis.

BWalnut said..
Great post!

1. In my case, would you recommend adding an 80L midlength board to my quiver? Or trying the same 96L board with a medium sized foil, like the North DW900? I'll probably end up getting both anyway. I feel I want to be on a little bit faster foil more often, but since the parawing doesn't give as much lift as a wing, I am afraid I won't be able to use my 820/142 setup as much as I want to.

When you start racking your brain on ideas like you have in this post every detail matters. 65l vs 80l vs 96l means very little to me. I've never found any correlation between volume and flight performance. Volume changes weight, length, width, thickness and those details tangibly change performance.

The way I view board dims impacting performance:
Length = pitch stability. If you want to offset this you can use a shorter fuse on your 820.
Width = roll stability. Changing your stance can help give you more leverage over a wider board to resist that stability.
Thickness = impacts on pitch, roll, and overall inertia. A shorter mast will offset this.
Weight = pumping and inertia influence. Nothing you can do to change this.
Volume = impacts takeoff and foil/sail selection.

2. Has anyone come up with any rules of thumb for the relationship between body weight, board size, foil, and stab for parawinging?

For example, in winds under 25 knots:
Board volume in liters = body weight
Front wing area in cm2= body weight x 11.5
Stabilizer area in cm2 = body weight x 1.7

I like the idea but I haven't isolated any equations here because, like you said, everything is so design, condition, and style dependent. However, this is why it's always so important to share all the details. Once you gather enough data patterns appear and you can develop something that has some general guidelines.

Thanks for the great input :) Your overview of how different board parameters affect performance is really helpful. The reason I'm focusing on volume is, as you mentioned, that it affects how easily you get up on foil and therefore how wide the wind range becomes with the parawing. It's obviously all a game of compromises.

I completely agree that my approach might be too simplistic and that every detail plays a role. Still, I'm unsure how I could come up with any kind of rule of thumb if I were to account for everything that might influence the outcome.

Maybe I'm going unnecessarily deep here... but that's what happens after a week of wind drought :(