To Improve Something You Must First Measure It.
I was recently publish by PowerPivotPro.com. These guys train Microsoft on the latest Microsoft Business Intelligence solutions. Rob Collie, Kellan Danielson and company are the best on the planet and I have become friendly with them over the past 4 years.
I proposed writing on article on some of the big data wrangling I was doing and they said
"Hey what about that surf Model? That looks pretty cool"
I am not sure if the TRACE works in Australia but if you appreciate Data, Analytics and Surfing you might like this article:
powerpivotpro.com/2018/02/power-bi-used-for-surfing-fun/
The graphic at the bottom of the page (in the link) is live and you can select waves to see how the visualization responds.

That's amazing stuff!
And those waves. 34 mph is 54 kph - that's fast. I use the Rip Curl GPS watch. My fastest is about 30 kph (which I did again the other day). But 54 kph - that's moving!
And a 17' elevation drop! That must have quickened your pulse! I would like to try that myself (he says from the safety of his desk chair.)
I tried Trace - I need to give it another go. I only tried it on my last Maldives trip and it failed miserably. It just did not want to play and the support people at Trace did not respond. Being an engineer I was curious to compare it to the Rip Curl record of speed, wave count, etc. I think that the Rip Curl watch does not sample as quickly, so if you need to be traveling in a straight line to get the highest speed (which may be physically true too, but sometimes you know you are going fast with turns and it will score you a low speed).
Have you had any great insights from the data?
How much faster do you go on the foil?
Have you determined that the fins made a difference to speed?
And I am curious to know how you make comparisons. How do you normalize the data? I guess you could use elevation drop.
Great article!
That's amazing stuff!
And those waves. 34 mph is 54 kph - that's fast. I use the Rip Curl GPS watch. My fastest is about 30 kph (which I did again the other day). But 54 kph - that's moving!
And a 17' elevation drop! That must have quickened your pulse! I would like to try that myself (he says from the safety of his desk chair.)
I tried Trace - I need to give it another go. I only tried it on my last Maldives trip and it failed miserably. It just did not want to play and the support people at Trace did not respond. Being an engineer I was curious to compare it to the Rip Curl record of speed, wave count, etc. I think that the Rip Curl watch does not sample as quickly, so if you need to be traveling in a straight line to get the highest speed (which may be physically true too, but sometimes you know you are going fast with turns and it will score you a low speed).
Have you had any great insights from the data?
How much faster do you go on the foil?
Have you determined that the fins made a difference to speed?
And I am curious to know how you make comparisons. How do you normalize the data? I guess you could use elevation drop.
Great article!
Awesome look at data :) I was surprised that was not faster. I frequently get 40kmh plus on waves. Best is 47kmh using a Garmin Fenix 3 and Strava.
That's amazing stuff!
And those waves. 34 mph is 54 kph - that's fast. I use the Rip Curl GPS watch. My fastest is about 30 kph (which I did again the other day). But 54 kph - that's moving!
And a 17' elevation drop! That must have quickened your pulse! I would like to try that myself (he says from the safety of his desk chair.)
I tried Trace - I need to give it another go. I only tried it on my last Maldives trip and it failed miserably. It just did not want to play and the support people at Trace did not respond. Being an engineer I was curious to compare it to the Rip Curl record of speed, wave count, etc. I think that the Rip Curl watch does not sample as quickly, so if you need to be traveling in a straight line to get the highest speed (which may be physically true too, but sometimes you know you are going fast with turns and it will score you a low speed).
Have you had any great insights from the data?
How much faster do you go on the foil?
Have you determined that the fins made a difference to speed?
And I am curious to know how you make comparisons. How do you normalize the data? I guess you could use elevation drop.
Great article!
Awesome look at data :) I was surprised that was not faster. I frequently get 40kmh plus on waves. Best is 47kmh using a Garmin Fenix 3 and Strava.
I need to get a Fenix 3, my watch goes too slow ![]()
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Have you had any great insights from the data?
How much faster do you go on the foil?
Have you determined that the fins made a difference to speed?
After measuring thousands of waves with my TRACE, doing multiple fin tests and swapping out fin boxes with Symmetric and Foiled and Zero Toe, Zero Cant fins, going Quad and Tri, Bi and Single I have realized that the speed of a board on a wave
IS SIMPLE TRIGONOMETRY
A 14 second period wave will move at about 20 mph (when it nears the beach). In general bigger waves move faster, typically the result of longer period energy.
Our boards start to plane at 10 - 12 mph. 15 - 17 mph is cruising. 20 - 25 is going fast. To go faster than 30 mph you will need an ANGRY, TERRIFYING 18+ Footer, a hearty breakfast and a sprinkle of pixie dust.

Surfers will say that they "Accelerated through the turn."
This always made me mad because turning required putting the board on edge, increasing the wetted surface area, causing the fins to engage and massively increase drag. This would typically SLOW everything down. BUT given an unstoppable force moving at 20 mph turning down the line does result in acceleration to cover more distance over time.
This is similar to a water-skier cutting across the wake behind a boat that is moving at 20 mph. In this scenario the fins, the board and its ability to hold an edge while NOT getting sucked over the falls requires a fast efficient configuration.
AND THEN WE ENTER THE AGE OF THE FOIL. TRAVERSING AT A 45 DEGREE ANGLE ON UNBROKEN WAVES TURNING 90 DEGREES AND COMING BACK AGAIN --> This is distance over time.
Being an engineer I was curious to compare it to the Rip Curl record of speed, wave count, etc. I think that the Rip Curl watch does not sample as quickly, so if you need to be traveling in a straight line to get the highest speed (which may be physically true too, but sometimes you know you are going fast with turns and it will score you a low speed).
I had surfing friends on 'prone' boards with Rip Curl watches. They would come back from the same session, same spot, same waves and show me their speeds. They were ALWAYS slower. I chuckled and thought SUP's were just faster (re-read the above and not likely). Then Jeff Clark got a Rip Curl. We did closer diagnostics vs. TRACE and now are convinced the Rip Curl reports 20% slower - All the Time.
Who wants that! So YES you need a faster watch.
Being an engineer I was curious to compare it to the Rip Curl record of speed, wave count, etc. I think that the Rip Curl watch does not sample as quickly, so if you need to be traveling in a straight line to get the highest speed (which may be physically true too, but sometimes you know you are going fast with turns and it will score you a low speed).
I had surfing friends on 'prone' boards with Rip Curl watches. They would come back from the same session, same spot, same waves and show me their speeds. They were ALWAYS slower. I chuckled and thought SUP's were just faster (re-read the above and not likely). Then Jeff Clark got a Rip Curl. We did closer diagnostics vs. TRACE and now are convinced the Rip Curl reports 20% slower - All the Time.
Who wants that! So YES you need a faster watch.
YES!! Vindication!!
(But are you sure it is only 20%
)
You have to wonder why. It can only be an error in the calculations. As per your explanation, to go faster you need to angle across the wave. Velocity is distance divided by time. The GPS should give accurate distance. And a watch should be able to accurately measure time.
But going back to your explanation, the greatest impact on speed is angle across the wave, but surely a) the fin would affect your ability to make the best angle (like a sailboat's ability to tack up wind) - or is it the edge of the board that has the greatest impact?, and b) the drag of the fin would impede the speed across the wave - but without surfing the same wave at the same angle with two different fins, it would be difficult to measure.
As for the proner's comments, I guess it comes back to the difference between speed (velocity) and acceleration. When you change direction, you have to decelerate and then accelerate again. But as you say, you never get back to maximum speed until you are zipping across the wave again.
Being an engineer I was curious to compare it to the Rip Curl record of speed, wave count, etc. I think that the Rip Curl watch does not sample as quickly, so if you need to be traveling in a straight line to get the highest speed (which may be physically true too, but sometimes you know you are going fast with turns and it will score you a low speed).
I had surfing friends on 'prone' boards with Rip Curl watches. They would come back from the same session, same spot, same waves and show me their speeds. They were ALWAYS slower. I chuckled and thought SUP's were just faster (re-read the above and not likely). Then Jeff Clark got a Rip Curl. We did closer diagnostics vs. TRACE and now are convinced the Rip Curl reports 20% slower - All the Time.
Who wants that! So YES you need a faster watch.
28mph = 45kph so my Garmin giving me about 40kpm on bigger days and 35kph on smaller days is in the ballpark. Get the occasional spike to 45 when I have to straightline big sections so cover a lot of ground.
But going back to your explanation, the greatest impact on speed is angle across the wave, but surely a) the fin would affect your ability to make the best angle (like a sailboat's ability to tack up wind) - or is it the edge of the board that has the greatest impact?, and b) the drag of the fin would impede the speed across the wave
With regards to fins and speed: Drag is proportional to Lift ~ 1/2 Rho V^2 where Rho is DENSITY of Liquid
I recommend GOING SMALLER IN BIGGER WAVES. The bigger waves go faster - PERIOD. When you start to get to 10++ feet the speeds get up to 25 or 28 mph. Going from 12 to 24 mph (e.g. 2X) means that Lift (hold on the face) and drag go up 4X. You simply DO NOT NEED that much lift. Meaning use smaller fins.
STRETCH one our prominent designers here in Northern California for boards at Mavericks says he uses 3 3/4" fins on his Mavericks guns.
Big fast waves --> Tiny stiff fins.
Super good Geek stuff Beasho , left me in your wake with this one , I'll have look harder into my Garmin Fenix 5 and Virb 360 didn't realise you could do that . Impressive .