High tech stroke analysis from Larry Cain with Canadian Olympic team technology

[PonoBill]

That's the basic problem--even if you measure it how will you interpret the results? At the time I built the paddle pod I tried using GPS for speed, and it was horrible. I didn't know about dopper for GPS and so I was averaging a bunch of locations and trying to extract speed from it. Give the limited location accuracy of GPS, the random distribution of the inaccuracy--in three planes--and the low speed of an SUP the speed measured was smaller than the error!

Even if I had been able to accurately measure the speed of the GPS sensor, it wouldn't necessarily result in a velocity I cared about--which was the velocity along the axis of the board. The tail swings--that adds to speed. On a finless board that would probably be the highest speed even if velocity along the centerline vector is nearly zero.

[blackeye]

Blackeye --

Speed over ground is not necessarily the fastest measure. We can both tack a sailboat upwind and I can get to the windward mark first, even if I'm a little slower than you, if I out-point you by enough. Similarly, an open water swimmer (or a SUP paddler) has to swim straight as well as fast. 

Ah, good point - VMG is where it's at. (I'd rather point lower and go faster! Makes me a terrible yacht racer. The best sail of my last regatta was hitting 15 knots on the way in AFTER the race. Big grins)

I'm referring to measures that are reproducible for training purposes (and I'm necessarily excluding flat conditions.) For these purposes, a slight shift in wind direction or speed or water chop and direction would render the boat speed (output) numbers from two training days totally meaningless but comparing the inputs would still yield great insight. The same considerations apply to cycling and all serious cyclists train by power. Which leads to another point, you and I are using the terms input and output differently. While I agree that power on the paddle (as measured by a strain gauge) may be an input (of the boat's speed), for training purposes it's primary utility would be as a measure of output (of the paddler's effort).

Ah, yes, its important to talk the same language. My interest is in comparing the technology and I presume yours is the paddler's conditioning. I think in terms of power input to the vessel (the paddler's output), and the resultant speed (BS, SOG and VMG) as an output. I totally agree with you that the paddler's conditioning and technique makes all the difference for speed, but the only way to see how that translates is to measure boatspeed. Largely uncontrollable variables affect SOG, but how we respond to all of that and max our VMG is what our brains are for and has only the BS component that directly relate to training. The parable of the turtle and the hare would be a simple example. Your outpointing me is another example). In the end I suppose the lesson is train well and go the right way. 

In my obtuse way I was trying to point out that GPS measurements are probably more misleading than useful in many circumstances, even if they were accurate. Pono's comment bears that out and says it more plainly. The finer and finer we try to measure stuff, the more we (should) realize that the measurements don't have the precision we need.  It's still fun to thrash out in discussion. If we had tons and tons of sensors and millions and millions of sessions, we could probably find some correlations somewhere. Not me though. I know just enough about stats to get into deep trouble.

A few years ago deep hi aspect ratio fins were being tried for stability because they slowed roll. I wonder if they could contribute propulsive force a la a rocking dinghy? Enough to overcome their addition to drag? A gybing fin might be best.

[SURFnTURF]

I too had noticed that the paddles of the fast guys,as well as my own, went slightly behind the feet though with little,if any, power being applied.   I've come to think of this as A "follow through", like hitting a baseball.  More than anything it ensures good form through the power phase. 
      On a related note, I recently picked up a 14'x23.5" 2014 starboard Ace. With my slower cadence,  I've noticed that the bulbous nose going up and down more than my piercing bow board, a lot more. When I turn the paddle over faster, the bow stays higher, and bobs less.   I wonder if a higher cadence might be more effective on this board, and if different cadences  suit different boards the same as they do paddlers. 
   

[Kaihoe]

I too had noticed that the paddles of the fast guys,as well as my own, went slightly behind the feet though with little,if any, power being applied.   I've come to think of this as A "follow through", like hitting a baseball.  More than anything it ensures good form through the power phase. 
      On a related note, I recently picked up a 14'x23.5" 2014 starboard Ace. With my slower cadence,  I've noticed that the bulbous nose going up and down more than my piercing bow board, a lot more. When I turn the paddle over faster, the bow stays higher, and bobs less.   I wonder if a higher cadence might be more effective on this board, and if different cadences  suit different boards the same as they do paddlers. 
   

The ACE is a completely different beast to other boards, with its tail it is really forgiving.  You can use big slow cadence strokes with it  that just won't work with other boards.  I even used to paddle behind my feet as I came over a wave to get a bit more push down the slope, can't do that with wider tailed boards.

Hi cadence still works with the ACE, I found it was more of a case of what the paddler was comfortable with than the board

[SURFnTURF]

Thanks for that input on the board.  Any other hints or tips that may help me dial in the board?

[Kaihoe]

Thanks for that input on the board.  Any other hints or tips that may help me dial in the board?

The stability is all secondary, you can lean the board so far that water comes over the side... so don't bother correcting it as it tips, just keep paddling. Once your doing it right you'll find it takes a few minutes to rewire your brain as you swap between boards.

Connor can kick turn it.. but I have no idea how