Takeoff Angle of Attack for Shortboard Vs Longboard

[@DepthWish]

I love the efforts of quantification that you are working on with your videos and thank you for them. I've applied my interpretation of some pieces from different episodes and it has been helping significantly in a short period of time. Specifically, I now put my max effort for kicks and strokes in just before the wave and until it pitches to about 30 degrees. Previously, I was putting my full effort at the point when I felt myself lifting which is kind of too late. Once the board is pitching, there is always some board and body in the water so that means arm strokes will definitely not be as deep as they would at the flat trough of the wave just before it arrives and at low ramp angles, so less efficiency in effort the more steep it gets. Please keep these videos coming!

[@RobCaseXSWIM]

Great insight. Just make your power strikes aren’t too soon. Paddle strokes in flat water without any backup force will just burn you out. No more than 3 power strokes are needed at the right moment. Cheers!

[@mynamesjeff4091]

Hey Rob huge fan of your videos, I look forward to learning something new from every future post on your channel. I believe I might have an answer to one of the question from this video. By no means is this hard facts but to my knowledge from what I have learnt over my years as a surfer and shaper about some key principles in surfboard design, physics and hydro dynamics the cause of a surfboards angle of attack regarding the paddle in phase as you are demonstrating in this video is due to the fulcrum position of the surfboard and the relation to the surfers center of mass during the acceleration to planning speed. This would be my simplified explanation to an other wise complex one due to the nature of the topic and how compound curves work on fluid. The sensation of effortless glide and wave catching ability more experienced surfers tap into from years of practice is the result of them figuring out how to better manipulate their center of mass on any given size surfboard more so than their physical strength. Technique trumps power in pretty much every surfing related situation.

[@RobCaseXSWIM]

I think you’re definitely on to something. The first two techniques in my Level 1 course are all about balance control. Balance control is key to everything! You are correct. From paddling efficiency to catching waves and adjusting that fulcrum.

[@zzzck]

I think you are looking at take off in linear fashion. It is more dynamic as different parts of a wave is being used to change the center changing nose to tail to adjust to different energy spots of a breaking wave as it lifts up and pushes and eventually plane and use gravity after you take off. I think taking into consideration of the shape of breaking wave; flatter trough, pitching crest, slab middle. As these could mean we are not speaking of angle of paddling but more maneuvers to get into a right part of the wave. Just a thought as I listen to you.

[@RobCaseXSWIM]

I love this thought and something we need to test in a standard environment like a pool where we might be more accurate in getting repetitive data. To your point though, a pool wave might only have a handful of profiles and within each profile different sections of the wave along the distance it travels. I completely agree this analysis is much too linear. It was more meant to get comments like this to rattle around in your minds and think of how we might actually test wave catching. Thanks so much!

[@bojador]

Nice video. Here’s an idea. How about eliminating the surfers interference? Same surfer, different size boards with the same volume/same size boards with different volume, and no paddling. This way you could see how much the wave can lift the board out of the water into planing for different types of boards only. I’ve actually been thinking if we should learn to catch waves without any paddling at some point in our surfing progress. Sure we can catch waves at less optimal times/positions, but should we start by learning optimal positioning first?

[@billytuchscher]

I surf a lot of reefs and have done plenty of "no paddle takeoffs" (I long board mostly, so have the advantage of a long tail to force the nose down the wave face), I get a certain satisfaction from those. Agree that positioning is numero-uno!

[@RobCaseXSWIM]

I like that approach to isolate the board variables. If we can somehow place a buoy or marker at the same exact location that would allow us to control another variable.

[@CharlesMarvin]

Something that might be interesting to discuss or add to the calculations here: the "squirt" effect occurs on the craft as the wave pitches and just before pop-up. Note how much of the craft is displacing water, and the displacement force is angling towards the direction of the beach.

[@RobCaseXSWIM]

Agreed! This is an area I've been thinking a lot about how we might measure that "squirt", the angle, etc.

[@billytuchscher]

Great questions, information & data. I mostly long board but own 8 short boards and shortboarding has made a HUGE difference in my longboard takeoffs. I can long board any break. Late takeoff "no problem!". -- in my opinion volume has no effect (at the point of takeoff), its all planing surface at that point. -- Great content. Thank you!

[@RobCaseXSWIM]

Definitely some truth to this but we need to put some science backed evidence to fully claim it. Great comment

[@mynamesjeff4091]

For anyone interested in how to manipulate your center of mass on a surfboard I suggest you start with an exercise called a superman rock. The principle of the technique is during your cobra pose/ arch back position while paddling you perform a superman rock as the wave comes into contact with your toes, the timing may differ depending on the wave. The initial impact of the approaching swell will assist you to paddle with higher hips and increased downward momentum. The trick is not to put your chin down on the board as most people believe but to thud your whole chest downwards performing a superman rock till your chin hits the board which levels out the surfboard to the surface of the wave. Once the board has leveled and you are essential paddling down hill you return to normal paddle posture with your chin raised to prevent pearling, allow space for a quick pop up and most importantly increase your ability to observe what the wave is doing. A really good eg of someone performing this well is John John. Rocks the chest down, gets the hips high, paddles once or twice glides down hill. Styles like it's no ones business

[@RobCaseXSWIM]

That’s a good dryland drill. I teach an in water drill that diagnoses whether a surfer uses their arms for balance control or their core. It’s a bit more difficult because the surfer is in water. If it’s determined that they are using their arms more for balance, then a dryland drill like yours can aid (as long as they have mobility) and they can work their way up to controlling it with the in water drill. Epic comment! Thank you!

[@lonbordin]

I've been riding since 1986 but I will admit not really paying attention to what I was riding or why... usually relying on the shaper or what was available in the store. Recently I've been doing a lot of investigation and reading on board physics and design. As your fantastic channel highlights there's an incredible lack of scientific data when it comes to surfing. I'm really looking to explore surface area and volume for my size (I'm a big guy 1.95m/112kg). I'm so envious of those people who take a few strokes on a 9' and are up and riding an unbroken wave. Saw a LOT of this in Biarritz recently! Doing some calculations I can extrapolate a board size for someone of my own size by dividing the weight of an average surfer (80kg) by my weight, then taking the square root of the answer. I use this number as a factor to adjust the dimensions of the board. For example if the average surfer weighs 80kg and rides a longboard 9ft long (108 inches) x 22 inches wide (76liters, fairly typical), and I weigh 112 kg, 112/80 = 1.4 The square root of 1.4 = 1.183. Hence the length/width (surface area) of the longboard for me would need to ride to be the equivalent of the 80kg surfer would be 108" x 1.183 = 10'8" and the width would be 22" x 1.183 =26". This would give me almost exactly the same surface area as the 80kg surfer has. We can do the same to calculate volume changes for weight, taking the cube root, which makes the differences slightly less. So 112/80 = 1.4 The cube root is 1.119 76 liters * 1.119 = 85 liters. I really appreciated your mention of surface area in the video. I think surface area being a function of square has a bigger role to play than volume in softboard design. Look forward to more content.

[@RobCaseXSWIM]

Great insight and approach to putting some science into your decision making for board selection. Agreed, surface area definitely plays a role. Case in point, I rode a 4’8” 25liter board at my local break which is actually designed for wakesurfing. It has a lot of surface area. Another example - surfing an alaia. Basically a thin piece of wood with wide surface area and some length. Definitely using surface area with volume should be investigated deeper. Maybe we can grab some shapers with math backgrounds to help enlighten us.

[@onshore1ft]

Fantastic information thank you

[@RobCaseXSWIM]

Thanks for the feedback!

[@tedpaff2587]

Great work and really interesting stuff Rob! A higher angle of attack for shortboards is kind of intuitive and is what most of us (I assume) feel vs surfing a longboard. But I am a little surprised but how large of an angle. I am curious if this research impacts any of your teachings on take-off technique? Specifically, it strikes me that anything that reduces the angle of attack for a shortboard faster will enable easier take-offs. With a 20 degree angle, we are pushing a lot of water until we start planing. Maybe makes the case for more kicking?

[@RobCaseXSWIM]

Great question Ted. It doesn’t impact what I teach in Level 2. In fact, it supports it even more. Remember that the paddle strokes only helps us get into the two other forces which help us get up to the to the speed of planing earlier than if we didn’t paddle at all. Because of increased form drag, the shortboard requires the use of gravity more than the longboard. That should sound familiar based on what you learned in L2 (recall the chart with the different ramp angles vs acceleration at each degree). What this observation deepens our understanding even more is that in some scenarios, specifically waves that develop faster snd steeper, surfers need to begin the process of getting to their feet even before the point of planing has occurred. They rely much more on gravity to take them all the way to planing as they are getting to their feet.

[@yasu4303]

Lot of interesting questions. If you need surf ranch guinea pigs, I am willing to sacrifice for science! 😜

[@RobCaseXSWIM]

More than welcome J! Though, we have a waitlist right now.

[@JRabbitA]

My son is a physicist. and a surfer. I thought of sending to him. then i decided not to...

[@RobCaseXSWIM]

Oh man, please do. I don't mind being wrong, and I love to discuss how an actual experiment might be set up. So many variables but I'm sure people smarter than me can figure it out.

[@rctrix9063]

At the risk of sounding cruel, there is a lack of scientific background here.

[@RobCaseXSWIM]

Agreed. Not cruel. In fact, I specifically mentioned that detailed research needs to be done and hopefully those with the resources to conduct such a study can get this going. This simply shows there could be a research question for an academic team to go after.

[@MACtic1]

Thanks. I learned absolutely nothing.

[@RobCaseXSWIM]

Lol! Honest but true. The video was meant to open up questions, not provide answers. Thanks for the comment