The fastest SUP race board comparison- planing vs. displacement hull by Robert Stehlik and Jeff Chang

Watch the video (filmed in 2015, 5 years after this was first posted):

This is an edited version of a board comparison first posted in January 2010.  

On a mission to find the fastest SUP race board shape

Planing vs. Displacement hulls- a SUP race board comparison written by Robert Stehlik (Blue Planet Surf) and Jeff Chang (Wet Feet) for Zen Waterman
When I first started paddling racing boards, the equipment was not as important as the technique and fitness level. I had a fast board, a 14' C4 Waterman Vortice XP and I kept going faster by practicing and improving my technique and endurance. While going on Hawaii Kai runs with Todd Bradley, Dave Parmenter and Greg Pavao, who were all riding the same board as me and going much faster, it made me realize that I had plenty of room to improve. It was me, not the board, that was slow. Getting a good, proven stock race board is a good way to get started in SUP racing. Most races have 12'6 or 14' stock divisions and you can be competitive in the class without getting caught up in the "arms race" in the unlimited division. The size and price of a stock board is also more manageable.

With that said, as I got better, I noticed that guys on longer, unlimited boards with rudders were going faster and at some point I realized that if I wanted to be one of the fastest racers, I also need to be on one of the fastest boards. Since then, I have been trying many different boards and designs in search of the fastest one and want to share some of the things I have learned.

My friend and training partner Jeff Chang and I had the chance to test and compare several SUP race boards. As Jeff and I train together regularly, switching back and forth with each other gives us a good indication of how fast we are going. Last week, we compared two new 12'6" stock race models that will be available as production boards next year and we can't report about yet.

SUP race boards- Unlimited displacement vs. planing hull

This week, we had a chance to compare two unlimited class raceboards. We compared a Sandwich Isles Composites (SIC) custom Starboards prototype shaped by Mark Raaphorst, and a 17'6" Dennis Pang race board that Guy Pere, Kamaki Worthington, Aaron Napoleon and myself have all won races on. I wrote about this board before in the Coast Guard race recap.

Dennis Pang (left) and SIC race board decks

The custom SIC/ Starboard board on the right is a planing hull with a flat bottom and sharp edges in the back and hard tucked under edges. It's quite wide and stable.

The Dennis Pang board is more of a displacement hull with a piercing bow and rounded rails in the nose and tail. The mid section has a slight double concave with soft tucked under edges. This board is only 25 1/8" wide with a flat area of 22 1/4".

We launched in Hawaii Kai and I took some pictures as Jeff passes me on the Dennis Pang board.

Doug Locke was on a 14' Naish Glide and Darin Kohara was on a SIC F-14.It was pretty windy and I was confident I would catch up to them on the SIC, but it was not as easy as I expected. The board felt like it was pushing water and I had a hard time catching the short, disorganized bumps. I paddled as hard as I could, but did not get closer to Doug and Jeff, who seemed to be having a blast connecting the bumps. To be fair, I have been riding displacement hulls for a while and have never ridden a planing hull over 14', so I had to get used to it. I know that some of the fastest guys are on this kind of board, so I made up my mind to figure out how to make this thing go. As we got further out, the bumps got bigger and more defined. I figured out that the board needed to go from bump to bump to maintain speed and that I needed to move my weight back quickly to pick up speed on a bump. I started getting used to the board and began to tap into some of its potential.

My understanding of the theory behind planing vs. displacement hulls is that a planing hull is slower at low speeds but once it starts to plane at higher speeds, it lifts out of the water and reduces the wetted surface, lowering friction and allowing higher top speeds. In comparison, a displacement hull uses a long waterline and smooth water entry and exit to allow for less drag at low speeds. You can get a displacement hull on a plane but the top speed is limited by water wrapping around the rounded edges versus the flat bottom and hard edges of a planing hull that allow a clean release, more lift, less drag, and higher top speed.

After getting half way to Black Point, Jeff and I switched boards and I got on the Dennis Pang board I was used to riding. The board felt very tippy coming off the stable SIC board and it took me a moment to adjust to it. When I finally got into the groove, I was catching every little bump with little effort. This board just feels slippery through the water; hard to put into words.

Jeff on the SIC catches a runner. Note how he moves the right foot back to lift the front of the board up.

Doug Locke is the master at catching and surfing bumps. He has tried many boards, too and really enjoys the 14' Naish Glide.

Jeff catching a swell coming into Waikiki

We finished at the Elk's club

Day two: We took the boards for another run the next day.

The SIC rudder system (ASS- Advanced Steering System) is comfortable and is easily controlled by the toes.

The wind was strong and the board was catching bumps without even paddling.
We had a big group of stand up and prone paddlers starting at the blinker buoy.
The second run on the SIC board went better. I was able to keep up with the fastest guys and I really started to feel the board's strengths, namely:
It's fast on the bumps and it maintains a high speed when connecting bumps.
Stable deck and thick rails, barely ever had water running over my feet.
Easy to control, especially when riding bumps and easier to ride swells at an angle or "down the line" at angles where the displacement hulls tend to roll and slow down. I figure this is a big advantage in the Molokai race where you are quartering the wind and swells for most of the race.

Jeff's truck with seven boards and paddlers ready to shuttle back to Hawaii Kai.

Board test day 3: On the third day we added a third board to the test: Jeff Chang's Bark board that he used in the Molokai race (the black one on the right)

Jeff's board is a displacement type hull, similar to the Dennis Pang board but at 26 1/2" wide is about 1 1/2" wider and more stable. It also has more rocker and cable rudder system that runs underneath the deck, like on the SIC. The Dennis Pang board has a fiberglass batten running down the deck that controls the rudder.

Jeff's BARK has a "knifey" piercing nose and tail with a double concave in the middle and rounded rails.

Launching in Hawaii Kai.

The crew at the blinker buoy.

The wind was light and the bumps were small, but it was great to get out on another beautiful day in Hawaii. This was the shortest day of the year and this picture made me realize how lucky we are to be paddling under rainbows when most people in the northern hemisphere are stuck indoors.
I rode Jeff's Bark the first half of the run and immediately felt comfortable on it. The board was predictable, fast, and fun to paddle. It felt lighter and more nimble than the 18' Bark board I own and paddled on in the Molokai race (see my previous post).

I am always impressed by how smooth the water entry and exit is on all the Bark boards I have tried. In flat water, the amount of turbulence created where the bow enters the water and the turbulence behind the tail is a direct indicator of how much friction the board has through the water. The less the water gets disturbed, the faster you go. Some boards slice through the water so smoothly that you don't feel like you are going fast- that's what you want. Joe Bark seems to have a special skill for making the water go under and around the board with minimal disturbance and drag. I have noticed that many of the shapers that make the fastest unlimited boards have been making and experimenting with racing boards (prone paddleboards and windsurf boards in particular) for many years and can draw from that experience to make the fastest hull shapes.

While a piercing bow with a "v" in the water entry area seems to be fastest in flat water, a flat bottom where the water enters gives more lift in the nose and is easier to control when riding the bumps. The wide flat water entry area of the SIC generates plenty of lift and is easy to control, but also feels like it is "pushing water" at lower speeds, while the Pang board is a compromise. When I switched to the Pang board, I had to get used to the tippyness again but once adjusted, I felt like the narrower board had less resistance through the water. The Pang board transitions from a piercing nose to a flat section where the water enters. This makes the bow "splashy" in flat water, not as smooth as the Bark, but also seems to make it easier to steer in bumps and it felt like I did not have to work as hard to catch and stay on the bumps. Out of all the boards I have tried so far, the Dennis Pang board is still my favorite for coastal runs and races, which is not to say that it would work well in the Molokai race (too tippy) or in a flat water race (water entry not as smooth). For those conditions I would probably choose the SIC board and the Bark, respectively.

That summarizes my input.

Here is what Jeff Chang (Wet Feet) has to say about the three boards:

Here are my impressions for the various performance aspects observations from paddling next to you. This is a good gauge because you are faster than me:

Overall speed:

In flat water is seems the Bark is fastest, Pang second and the SIC third.  This is easiest to measure.

In moderate winds it seems the Pang is fastest, the Bark second and the SIC third. For me the Pang is faster because is seems to miss less of the bumps, especially the smaller ones. It seems easiest to catch everything. It felt like the Bark and SIC missed more bumps and I could feel more often stalling on the backside of the bump and needing to wait for the next one.  But also it seemed like once you caught a bump the Bark and SIC glided further.  The SIC especially so if the bump was big.  So overall if feels like the Pang catches more bump and maintains the speed better but I got longer rides with the Bark and SIC.  I think a lot depends on the paddler too.  For example, someone like SIC with a lot of strength might be able to make a board like his go faster (or Scott Gamble on his Bark) than I could and could close the speed gap between the three or even make his go faster than the others.

Stability:

SIC most stable, Bark second and Pang third.  Although the Pang was not overly tipsy and was easy to recover on.  During the HK run I don't fall atall using the Pang so the design is reasonably user friendly.  But others have commented that at 25" wide the Pang is hard to balance on and if you cannot balance then you cannot put full paddle power into your stroke.

Paddling Effort:

Pang easiest, Bark medium, SIC most effort.  Again you need to be able to balance on the board to be able to power it properly.


Handling:

The SIC board is very stable with a lot of volume and feels like a boat. I can see this being very good for Molokai where if you need to you could just cruise and not have to concentrate on balancing.  The planing type back would also be good for turning the board to windward and trimming on a bump which is critical for the channel.  I think a board like this would be my choice for the channel.

The Bark is very stable and user friendly but a little more nimble than the SIC and is good all around since in goes fast in flat water.   This is a good Oahu board and is good for the HK run since the start and end are in flat water and the board catches bumps well.  It would also be my choice for a North Shore race.  The double concave bottom and pronounced spine down the middle seems to give it a lot of drive and might explain the longer rides. I rode this board at the last Molokai and at times it would have been nice to have had a more stable board but then this board is light and easy to paddle so hard to say if I would have gone faster on a more stable board.  Its always a tradeoff.  I was very happy with my Molokai time on this board and felt good at the end so after all is said and done maybe a more stable board might have been more comfortable but also might have been slower.

The Pang feels fast and slippery in the water.  For me this board was the fastest and most fun to paddle because it seems to catch the most bumps and maintain speed although you don't get those really long rides where you feel like you are surfing.  But in a race it seems catching all those little ones and maintaining speed is faster than those longer rides which happen less often.  This might be explained by the more subtle concave bottom and flatter more neutral entry just behind the piercing nose.  I think that is what gives it that controllable feel dropping into the bumps and ability to push into the next one.

Thanks for reading, Aloha!

Updates:

9/28/2012:

Since this post was written in January 2010, Jeff Chang had Dennis Pang shape him a copy of the board in this comparison and had it glassed very light with carbon.  He installed a cable rudder system and has been winning many races with this board over the last few years.  For pictures of his board and the rudder system, visit this Molokai training post.

I (Robert), have gotten used to riding planing hulls and now prefer to use them in downwind conditions.  I have been using a 17'4" SIC Bullet or the 14' x 28" Blue Planet Bump Rider that I designed specifically for downwind races.  No longer happy just using boards created by others, I started using computer aided design to shape race boards in 2011.  This has allowed us to make incremental improvements to the shapes to make them faster and improve handling.

Robert Stehlik on the 14' x 28" Bump Rider

Race proven shapes:  Greg Pavao and Robert Stehlik won their age division and came in 3rd overall two man team at the 2013 Molokai to Oahu Race on the 14' x 28" Blue Planet Bump Rider model.  The planing hull design make it a fast and stable board in downwind conditions.

August 2014 update:

Jeff Chang finishes the 2014 Molokai race on the latest version of the 14' x 28" Blue Planet Bump Rider.  He not only finishes first in his age group but his time of 5:23 is also faster than all other paddlers over 50, including those on unlimited boards.  Well done Jeff!

The last few miles of the Molokai race are the toughest part.  Jeff Chang powering through the rough waters at Portlock point.  This is the ultimate test of his willpower, stamina, technique and equipment.

Jenn Lee paddled the 2014 Molokai race on a new 17'6 x 26" Blue Planet Unlimited board prototype, a planing hull shape optimized for open water racing.  She improved her personal record by over 45 minutes.

Related posts: SUP Weight test: is lighter really faster?

Unlimited SUP flatwater speed test

12'6" flatwater speed test

Blue Planet board construction information and factory tour video

Narrated Downwind coaching video

Molokai Race training video

Aloha,

Robert Stehlik

www.blueplanetsurf.com

On Paying Attention As The Way of the Waterman: Part 1 - by Len Barrow

I have two heroes that have helped bring great happiness to my life. They come from two seemingly divergent backgrounds. What stuck me was their ideas about their arts came to the exact same endpoint: You must pay attention.


The first role model is and was the great surfer/shaper Ben Aipa. The other individual is my Roshi or Zen teacher Robert Aitken. He is currently 94 and still as sharp in wit and way, true to his Zen study. It would help a little to talk of his background. Aitken Roshi was imprisoned in a Japanese camp for Westerners during World War Two. He could have had the option of hating the Japanese (as most of us would), yet instead he embarked on the study of Zen in the prison camp itself. After the war he continued his study and was ordained a Zen master in an eponymous line of Japanese Rinzai Zen sect, the first Westerner to do so. He came to Hawaii and taught and established the Daimond Sangha Zen Buddhist center. He is considered as one of the primary founders of Zen in the west along with Daisetsu Suzuki and even my father, T. Barrow.

 The hardcore Surfers path which crosses roads with the Zen path, as I shall explain, stands in a dichotomy to our modern “worlds” of hyperactivity, cell phones, texts, Facebook, the internet and 60 hour weeks. Sadly, in everyday life, many of us move around like automatons. I know people whose lives are devoid of passion and interest. They drive to work from a suburb every day in grueling traffic. This is then followed by a job that they dread and another hour drive home in a moving parking lot. They then go home to their three bedroom home (that looks exactly like the next) in a planned suburb subdivision which sits on rezoned public land. It is as if we are taught to be Lemming competitors in a suicidal race to the nearest cliff or black whole. If this is the American Dream then I am terrified of it. This is not a dream, This is a hallucination.

 This may be an overly grim depiction of our culture yet I am not alone in my sentiments. Many surfers and water people are what psychologists call “non-normative” (not normal) and rapidly figure out what is happening is “lame” and decide on another course of living that they see as more sane. Many surfers are also attracted to different patterns of thinking (as opposed to Occidental or Western models) which include Asian philosophy and even Zen Buddhism in its scope. In these models surfers are more “normal” and actually quite sensible in their views.

 In my early twenties I was bombarded by society with criticisms of my lifestyle as an avid surfer. You see, surfing is seen to be cute when you are in high school and the girls love you, yet surfing loses its mystique to others as a person gets older. One may ask why? In Anglo-American culture one is taught to shed his childhood “habits” of play (such as avid surfing and other fun things) and get on to the Protestant work ethic. As a Religious Scholar , I have studied this phenomena anthropologically. This work ethic (as Described by Jon Calvin and Martin Luther) is directly related to ones goodness. Jon Calvin believed in predestination. In other words you are predestined to go to Heaven or Hell. It has been decided by god before you were born. Yet, there is a twist to this. A sign that you are going to heaven is seen to the degree too which you are hard working and well off. A sign that you may be going to hell is if you are poor and supposedly not working hard. When I studied these ideas as an Anthropologist I understood why I was maligned by so many. The people that criticized me were not doing so consciously. They were doing this because it was part of the Protestant, Anglo-American narrative or Mythology which was drilled into everyone from a young age hence when they saw a person who was “not with the program” they reflexively criticized or marginalized the person. Some how, I missed out on the message of this narrative.

In the past my mother had routinely called me “Lose money” or “Beach Dum” (not a typo). I watched in horror as many of my childhood hardcore surfer friends were sucked up by society. They quit surfing, sometimes at the urging of their wives, got full time jobs that they hated and rapidly became mechanical, uncreative and depressed. One of my good friends told me that his wife should allow him to surf as it was better than a psychiatrist’s bill. I still have the common experience of being given the “stink eye” by strangers as I drive to the North Shore in my dilapidated 71 VW van with board in tow, God forbid, on a workday. I was even told semi-jokingly by an economist friend that I was part of a “superfluous population” that included the very poor that were not factored into his economic models that he learned in school due to the fact that we barely spend any money on products hence cannot be profited off of in the “Free Market”.

In my twenties, I was both perplexed and angry at Anglo-American society. I was being accused of being lazy hence going to Hell for pursuing surfing. My friends followed the protestant work ethic to the “T”; hence were on a strait shot to Heaven. If this were the case, why were they miserable, depressed beings in life!? Surely there existed something amiss in this situation.

Please don’t get me wrong. Hard work is good, in fact I spent a full fourteen years to attain a Ph.D., but to go overboard by working maniacally to myself sounds strange.

My frustration about being a frenzied surfer in Anglo-American society was relived by forays in to Asian philosophy which my father urged that I take. In fact he arranged for myself a meeting with the esteemed Roshi who was described earlier in this paper.

My first meeting with Zen Master Aitken Roshi was wonderful. For the first time in my whole life, I felt justified in my decision to be a surfer. I was interviewed by the Roshi in the normal ritualistic manner. He sat in a tiny room and out of protocol, one had to crawl in, bow over the threshold and then make a 45 degree turn and bow toward him. I totally screwed up the process and was rather embarrassed. Surprisingly, the Roshi gestured to me and told me not to worry about it. There the Roshi sat, in his full Zen regalia and staff. It totally blew me away, as it was the first time that I was participating in a culture other than my own.

The conversation that ensued altered my life forever. I had come to him as I had been struck by an idea while surfing and staring at the ocean. I will let the ideas unfold in a question and answer format as this was the format that was required when one is engaged with a Zen master of Aitken’s standing. The conversation went something like this:

Len: How are You?

Roshi: How are You?

Len (perplexed): Pretty Good, I guess.

Roshi: What do you do?

Len (blandly): I surf, go to school, and I take care of a family in Kahala for rent.

Roshi: Then you are a caregiver.

Len (surprised): Yes, that's true

Roshi (attentively): How is your father?

Len: He is well and he collects books on Zen. In fact he has a huge collection that drives my mother nuts. She says the house will sink one day due to the weight of the books.

Roshi: Good. I must see it one day

Len (impatient): You know, I was struck by an idea. I had learned in my physics class that the equation E=MC² was that matter was an interplay of energy and energy was and interplay of matter. In fact they were different aspects of the same thing. I also learned that energy is conserved and that you could not destroy our create it. Well Roshi, I did a little bit of thinking and was blown way. If E=MC² applies to me, as it must due to the fact that I am an interplay of matter and energy (what the hell else could I be I thought) I am neither created nor destroyed, neither alive nor dead, in fact there cannot be coming or going. I was also surprised to find that Einstein called the notion of self as an “optical illusion of the mind”.

Roshi: You surf right?

Len (irritated: what kind stupid answer was that?): uhhhhh, Yea

Roshi: It is partially due to surfing that you have some insight of no coming, no going, no life, no death, no creation nor destruction. Roshi rang a little bell which means “now get out”. I did my bows and left excitedly.

I was utterly amazed. For my whole life, I was taught that my world view was not only incorrect but I was going to burn in hell for all eternity for it. Here was a little old man, who had nothing, sat in a little room and meditated extensively. He did not even surf yet he bizarrely came across as the most experienced surfer on the planet. How did he know my experience came in the surf or because of it? That he said I had a little insight, was a tiny nod to my E=MC² babble. I was so happy that I was not the only one to think like this and was even more thrilled to get a type of approval (albeit tiny)from a master of the Roshi’s caliber. It was a great affirmation for my self and for my choice of a surfing path. It was a turning point in my life and I have been on a happy path ever since in my study.

The Roshi suddenly “peered” out the door and stated with an amusing smile: “When you get thoughts like that just move on and by the way.........How can you practice if you don’t pay attention?

” I am not a Buddhist but this little Koan (Zen riddle) has taken me a long way. It is OK to be an avid surfer and pursue a path of peace and concentration rather than that of hyperactivity, inattention and conformity so engraved in parts of Anglo American culture.

Thanks Aitken Roshi

Altken Roshi recently passed away and this article is dedicated to him in the most humble and thankful form possible.

Aloha Nui Aitken Roshi

Blue Planet SUP clinic/ demo day Nov. 6th 2010- By Fabrice Beaux

A great way to share the stoke and fulfillment we find in the ocean is to teach others.  It's rewarding to help people that usually don't venture into the ocean  find a new way to get plugged into nature and enjoy the sensation of balancing on water. 

This is a short video of the Blue Planet demo day on Saturday Nov. 6th, 2010
Board design clinic by John Amundson and Kevin Seid.
Edited by Fabrice Beaux.


Blue Planet SUP clinic/ demo day Nov.6.2010- Board Design Clinic from Zen Waterman on Vimeo.
Board design clinic with John Amundson and Kevin Seid, Blue Planet Stand up Paddle clinic and demo day at Ala Moana beach park, Nov. 6th, 2010.


Edited by Fabrice Beaux.
Special thanks to the Hosts:
Blue Planet Surf,
Boardworks Hawaii,
Aquaglide,
Wet Feet,
Everpaddle,
StandUpPaddlesurf.net

And supporting staff:
Dr. Dan Rodrigues, Chiropractor
Doug Hopkins, Aquaglide
John Amundson, Aquaglide
Jeff Chang, Wet Feet
Karen Larieu, Wet Feet
Jared Vargas, Pro Racer
Kevin Seid, Everpaddle
Evan Leong, standuppaddlesurf.net
Sean Moore, Blue Planet Surf
Cameron Woodall, Blue Planet Surf
Andrew Giletti, Blue Planet Surf
Robert Stehlik, Blue Planet Surf
Kaipo Guerrero, Boardworks Hawaii
Fabrice Beaux, Video, editing

For future SUP clinic dates and more information, please visit:

http://blueplanetsurf.com/pages/free-demo-clinic

Aloha,

Robert Stehlik

www.blueplanetsurf.com

Is lighter really faster? SUP weight experiment- by Robert Stehlik

This entry is kind of off topic for the Zen Waterman blog as it is a technical description of an experiment I conducted, although it does tie into paying attention and being focused.  If you are interested in the interplay of weight and acceleration/ speed/ momentum on stand up paddle boards you might find it interesting.

I was inspired to test the effect of weight on speed in Stand Up Paddle boards when I was reading a discussions on the Stand Up Zone forum titled "Heavier Boards Faster?".
You may want to read it to understand the discussion that let to this experiment.  I will use some of the things I wrote in the discussion and will try to add details and information here that were not covered in the forum discussion.



The setup:
The short video clip above is a test of the GoPro camera and shows the set up used for the test.
Board: 12'6" x 29 1/2" Amundson Touring/race board.  For more information on this board, please check out the Aquaglide brochure.  I chose this board because it is stable enough to handle 30 extra pounds without making it difficult to balance. It has 247 liters of volume, so it can float up to 247 kilos= 544 pounds.  It weighs just over 30 lbs, so adding 30 lbs roughly doubles the weight and should make a measurable difference in speed.  I was concerned that using less weight would make the speed difference too small to be significant and measurable.
In the video: GPS and Go Pro cam taped to board: to record the speed on the GPS with the camera to see how the weight affects acceleration/ deceleration and top speed.

The 12'6 Amundson has a sealed insert on the deck. I screwed in an old windsurfing unversal and used it to tie off the weights so I could not lose them.

My weight is just under 200 pounds, the board itself weighs just over 30 lbs, I added 30 pounds on the deck for testing.  Although the board weight is doubled by adding 30 pounds, if you consider the weight of the rider + board, the weight difference is 230 lbs vs. 260 lbs with the extra weight, or just 13% more, and I'm assuming results would be different with different rider weights.

Test Day #1:
Here are the results of the 400 ft sprint test:

with 30 pounds extra weight:
Run 1: 49 seconds
Run 2: 49 seconds
Run 3: 48 seconds

without extra weight:
Run 1: 45 seconds
Run 2: 45 seconds

The acceleration was noticeably faster with the lighter board and the 3-4 seconds difference is significant.

For the half mile test, the results were less pronounced but still significant- as follows (wind was light 2-5 knots):

with 30# extra: Upwind: 5:44, downwind: 5:29 
without extra weight: upwind: 5:32, downwind: 5:16

I calculated a 3.6% speed difference upwind and 5% downwind

Here is what I noticed watching the videos of the half mile tests:
With the 30# extra weight it took me 7 seconds and 8 strokes to accelerate to 5 mph
Without the extra weight only 5 seconds and 6 strokes.
I also noticed that the weighted board has more of a wake and turbulence behind the tail and seemed to make more noise over the water


Test Day #2
I re-did the sprint tests the next day as the speed readout on the GPS was not visible on the video of the sprints.
I did not think the weight distribution would matter for the speed test but was urged to try to spread out the weights over the length of the board by one of the commenters.
To my surprise, the board seemed to handle a little better with the weights spread out than with the weights in the center. I tried to figure out why and then it made sense- with the weight spread out over the length of the board it yaws less (meaning less side to side rotation per stroke) especially from a standstill.
I know you could turn this into another science project but here is the simple explanation I came up with: Think of doing a flip off a diving board: you can speed up the rotation by pulling in your arms and legs closer to the center of rotation, while spreading out arms and legs- weight away from center of rotation- slows down the rotation. Same thing on the SUP. If all the weights are at the center of the board, it will yaw more easily (center of rotation is center of board), while spreading the weights away from the center of rotation makes it yaw less- makes sense, right?
A takeaway from this is that if you pack gear on your board, placing it away from the center- towards the nose and tail- will make the board yaw less than mounting it in the center of the board.

On the second day, the results were as follows:

400 ft sprints:

with 30 pounds extra:
Run 1: 48 sec
Run 2: 48 sec
Run 3: 48 sec
Run 4: 49 sec

Without extra weight:
Run 1: 46 sec
Run 2: 46 sec

So results were a little less conclusive as the average results were almost a second faster with the weights and almost a second slower without than the day before. Still significant though.
You can watch the videos below of the sprints without and with extra weights and draw your own conclusions.
Run without the weights: 46 sec. top speed: 6.7 mph


Run with the 30 lbs weight: 48 sec. top speed 6.4 mph



I realize that putting the weights on top of the board is not the same as having a heavier board where the weight is spread out over the entire hull.  Nevertheless, I'll assume for the sake of this experiment that the effect of extra weight is similar.

I rounded the sprint results to 3 seconds slower with 30 pounds extra weights. For the 48 second time that is a difference of just over 6 %


I'm assuming that each additional pound has a proportional effect on speed, so 6% divided by 30 pounds= 0.2%

So, I'm assuming that a pound of weight added to the board makes it 0.2% slower.

So, you would expect 5 extra pounds to make it 1% slower and 15 extra pounds 3% slower

This sounds very minimal and if you are cruising or touring: who cares if you are going 1% slower, that's only 36 seconds per hour of paddling.

I just want to put it in perspective from a racing standpoint.
Imagine for a moment that you are Rob Rojas and just finished the BOP Elite race in 1:03:15
If you want to check the results:
http://raceresults.eternaltiming.com/index.cfm/20101002_Battle_of_the_Paddle.htm?Fuseaction=Results&Class=Elite+SUP+Individual%7EOpen+MElite

So, you finished the Elite race in 15th place- a respectable finish against the world's top SUP athletes, but not top ten, no podium, trophy, prize money, shaking Jerry and Sparky's hands, pictures in the mags and on the web etc.

Matt Becker, on the other hand, finished in ninth place in 1:03:08. His time was 7 seconds (or 0.185%) faster and he makes the cut.

If you knew that making your board just one pound lighter would have made you 0.2% faster would you still say that weight does not matter?

I think not.

Another thought:
The speed difference might seem very small in the controlled flat water test but in downwind racing it's all about catching and connecting bumps. That slightly faster acceleration can be the difference between making and missing a bump, which can compound the effect. If you race in downwinders you know that connecting one good bump train can put you 50 yards ahead (or behind if you miss it) of you competition, and it does not really matter if you are at the front or in the middle of the pack.
If you are not racing, or want a board to train on, save yourself a bundle and get a solid, less expensive board, but in racing, light weight is KEY

Note: The test used weights on top of the board, not evenly distributed. Also, I used the sprint results to calculate the 0.2% effect per pound. Most likely the difference would have been smaller with even weight distribution and over a longer course. My estimate is that one extra pound, evenly distributed will make the board somewhere between 0.1% to 0.2% slower and maybe less than that in some circumstances.  Other factors are size, volume and design of board, rider weight, etc.  I'm thinking a displacement type board should be less sensitive to weight than a planing hull, which has to lift out of the water to plane and reduce wetted surface and drag.


This is just what I'm taking away from this experiment.  To read what others thought of it, or if you want to make a point or comment, please check out the discussion thread at:

http://www.standupzone.com/forum/index.php?topic=9446.15

Aloha,

Robert Stehlik

www.blueplanetsurf.com