Saturday, November 20, 2010

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.


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.


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!


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

Robert Stehlik


  1. Hi. We appreciate the effort you went through to report, but it seems to me you would have a lot more substance to this if you simply employed GPS and compared how you did on each board in each condition, on a simple grid.

    Sure, it wouldn't be perfect, but it would be a lot more substantive and informative.

    Especially nice if you'd report wind speed and your height/weight.


  2. Hi Ri,
    Thank you for the comments. I'm actually pretty anal about measuring and keeping detailed records. I have been using the controlled flat water conditions of the Hawaii Kai marina for measured training runs to test my training progress and compare different equipment. You can check my training log spreadsheet at:
    My weight fluctuates around 195 lbs and my height is 6'2".
    I wrote a post about a weight experiment I did in flat water conditions with GPS and timed runs here:

    The problem with using GPS data is that the variables often make the results inconclusive. Even on flat water, with no wind and no currents, it is impossible to put out the exact same power output on two consecutive runs. If you look at the training log spreadsheet you will see that even on two consecutive runs in the same flat water conditions with the same gear, the total time can vary by as much as 25 seconds or 4%, which is a significant difference and due only to different power output between runs. In comparison, a board speed difference of 1% can be substantial when racing.
    Despite the variables, I find the measurements useful in flat water conditions with very light winds where the biggest variable is the output of the paddler and other variables can be minimized. If you measure enough runs, you start to get usable results.

    In the open ocean there are many additional variables, including currents, which depend on the tide and the line chosen. Wind speed and direction will vary over the length of the course and if the wind has been strong for several days, the bumps tend to be bigger and more defined than on the first windy day, so even if you record the tidal phase and average wind speed it still won't give enough indicators to compare conditions. No two downwind runs are ever the same which is why comparing times on two runs with different gear will not give you conclusive results about the speed of the gear used as most of the difference could be a result of the conditions.
    I have found that the only way good way to subjectively compare equipment in downwind conditions is with a training partner that is close to your speed and bump riding skill level. If you are paddling next to each other in the same conditions and switch boards back and fourth, small speed differences will become obvious and will vary in different conditions.
    As we reported, the displacement hull of the Bark was fastest in flat water, the narrow and fast Pang worked best in smaller bumps, while the stable planing hull of the Mark Raaphorst shape worked best in rough/ windy/ bigger bumps type of conditions. So, no one board will be the fastest in all conditions and of course the ultimate test for equipment is how you do with it in races. Also, your motor will make the biggest difference in the results, not the board. The difference in board speeds is often a small fraction of a percent.

  3. For a timed speed test in flatwater that we recently posted, please click on the link at the bottom of the post.
    (Unlimited SUP flatwater speed test)

  4. Hi,

    Just want to say nice articles, really enjoy the 12.6 test results.

    Great job.


  5. Thanks for the feedback, Chris, glad you are enjoying the blog.
    Aloha, Robert

  6. Extremely useful i would like to put a link of this in my sup school!
    well done

  7. Please feel free to share or link to this information, of course. I'm glad you find it useful.
    Aloha, Robert


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