Paddleboard Speed

[rkdjones]

I just timed myself on my 12x32 surfboard (non-displacement).  Paddling hard over a 1 mile course, I averaged somewhere around 3.6 mph.  I had a little wind in one direction.  I just bought a displacement 12-6x29 and am curious to see how it compares.  (I would love to see what my peak instantaneous speed is.)

Robert

[PonoBill]

Back in the very early days of this forum there was a pretty heated argument about whether the big difference in a SUP race was the board or the motor. Somehow in the process I wound up with a Penetrator (actually I remember how it happened but it's a longish story). The point is that we wouldn't have the same argument today--at least not about flatwater paddling. There are a LOT of really good paddlers, and while there's a pretty big difference between an elite racer and a ordinary racer, I don't think there is anyone who has been paying attention that wouldn't agree that if you put a really great paddler (lets say Connor Baxter) on a 12' board, and  an equally good guy who lately comes second to him (say Dave Kalama) on an unlimited board, that Connor won't be able to see Dave after about 15 minutes. Dave would be 1.5 miles per hour faster than Connor. And there's not much room for debate about that.

What has changed is that pretty much everyone understands the kind of barrier that hull speed represents. A intermediate paddler rarely reaches hull speed except in sprints, because it's harder to make the board go faster as you approach hull speed. The really fast guys operate at hull speed, and sometimes edge a little above--mostly by reading water really well, because there's really no such thing as flatwater, but also just by motoring up that steep curve. But the difference between fast and slow is .2-.4 mph. when board lengths are the same. That's 5 to 10%. That's huge. But it doesn't look like it at the beginning of a race.

[Piros]

Back in the very early days of this forum there was a pretty heated argument about whether the big difference in a SUP race was the board or the motor. Somehow in the process I wound up with a Penetrator (actually I remember how it happened but it's a longish story).  

I remember that thread well Bill , allot has changed with the boards since then and so has stroke technique and the paddles , an elite paddler will be able to hold a much higher and intense stroke rate to your average padder. I personally don't believe there is a paddler that can take the 2011 model top race boards to their maximum hull speed and if they could you would see an immediate design change. Connor Baxter's starts off the line are so explosive and there is no sign of that board pushing water out front and holding him back.

So to answer the question how fast how fast can a SUP go...we don't know yet as fitness levels , board and paddle design keep evolving it will only get faster as the sport is still in its infancy.IMHO

[SUPpaddler]

Must read material below from the kayak world on speed vs. resistance, and how wetted surface and wave-making ability contribute to resistance.  This compares 18 touring and racing kayaks with waterlines of 14 feet (some of the 16.5' boats) to 20 feet.  Simple to understand, with the conclusion that trying to sustain speeds over 4 knots (4.6 mph) provides vastly diminishing returns.

The average of these 18 kayaks, all faster than most SUPs, requires more than double the effort simply to go from 4 kts to 5 kts.  Longer waterlines actually have more resistance at lower speeds because of increased wetted area (the least wetted surface area being a hemisphere), and don't produce more speed until paddling at an exercise pace for most paddlers. 

For any given waterline length, the hull's shape, as largely determined by its width, roundness, and rocker seem to determine its speed for a given effort.  These factors are incorporated in what the article calls a "prismatic coefficient."

I've had kayaks of all sizes and shapes, and a reasonably sleek 13' - 14' hull is probably the sweet spot for maintaining that 4 knot touring pace, reserving a little more speed if you want to push it.  Waterlines below 12 feet top out too quickly, and above 14 feet is mostly wasted except for exercise and racing.  I'm assuming this translates well to SUPs.

See http://www.seakayakermag.com/2007/07e-newsletters/December/fastkayak.htm
               
and

http://www.seakayakermag.com/PDFs/Kayak_Reviews_Info.pdf

[rkdjones]

It would be great to see analysis of boards comparable to the analysis Sea Kayaker reported for kayaks.  For those of us that are not surfing, this sort of analysis should tell a lot.  I knew that the rounded hulls minimized wetted surface (a sphere has the smallest surface to volume ratio).  But I still have no good sense of the speed at which length becomes critical.  I do find it interesting that the graph indicates that it takes 8x as much power to double the speed of a kayak from 2 to 4 knots (well below hull speed).

Matt Broze (kayak builder legend here in Seattle) made a 14' kayak that he claimed was just as efficient as the longer boats at cruising speeds.  But I am not aware of any 12' kayaks that were considered efficient designs.  I'm thinking that 14' is the right length for a recreational flatwater board.  Robert

[pguidry]

I'm doing even worse.  I took my 10'5" Starboard Widepoint on this trip yesterday: http://treksee.com/p/11f5a

It took me 2.5 hours.  It was 6.5 miles by the website.  I'm sure I didn't go "straight" and a bit of looky loo'ing but 2.5 hours?  I guess I need more practice.  I did the same paddle 3 weeks ago but added another island for 10.5 miles, it took 5 hours.

[bbarry]

This is really in response to PB's post about ultimate speeds.  Need to remember that the standard hull speed calc is for knots, so in our world we need to increase by a factor of 1.15.  So for today's typical flat water raceboard with every lineal inch engaging water line under way it works out to more like 5.45mph for a 12'6" (11 minutes per mile) and 5.76 mph (10.4 minutes per mile) for a 14.   

In glassy conditions I can hold my Bark Competitor (12'6" )to around a 12 minute mile for 4-5 miles and my Starboard Coast Runner (14) to around 11:40 for the same distance with a personal best of 11:21 for 6 miles in a recent race.  At around 15mph downwind I can exceed hull speed on the Coast Runner.   Never had the Bark on a non tidal or current impacted course to verify but I am sure it easily exceeds hull speed in moderate wind.

Bruce Barry / Seattle

[PonoBill]

Well, I guess I was wrong, we can still have this argument.

[aconstruction]

A handy hull speed table can be found here
http://www.frontrower.com/hullspeedchart.htm

[JC50]

I'm doing even worse.  I took my 10'5" Starboard Widepoint on this trip yesterday: http://treksee.com/p/11f5a

It took me 2.5 hours.  It was 6.5 miles by the website.  I'm sure I didn't go "straight" and a bit of looky loo'ing but 2.5 hours?  I guess I need more practice.  I did the same paddle 3 weeks ago but added another island for 10.5 miles, it took 5 hours.

Do you account for current, both wind and tidal?

IMO, the only way to accurately measure your speed is not with a GPS, but with something like a SpeedCoach and attached impeller to hull, thus eliminating all the issues with using a GPS or time-distance formulas.

Hull length - Hull speed tables seem to produce a good ballpark, but I would think are still just an estimate considering the varying board shapes/lengths and paddler weights.

[SUPpaddler]

Simple speed/resistance test using a fishing pole, grocery scale, and a gps –

On the shore of a calm lake, take the hanging style of grocery scale (should measure up to about 10 pounds in small increments) and affix it horizontally to a post so it measures resistance when you pull on the hook.  Connect its hook to the very top eyelet of a fishing pole.  Connect the end of the fishing line to the bow of the test board and position the board about 100 yards off shore.  A rider of a selected "standardized" weight stands on the board with gps. 

Now, crank in the board with the fishing pole at a consistent pace and constant resistance on the scale, while the rider records the speed.  You now have one point on the speed vs resistance curve for that board.  Repeat, cranking the board in at slower or faster paces and record resistances and speeds, making sure you get good coverage within the 2 to 7 pound range of resistance.  Soon you should have a complete curve for that board like the one for kayaks linked in an earlier post.  Repeat test with other boards.