Sunday, February 1, 2015

Stand Up Paddle board volume explained- ways to determine the proper board volume



We are often asked: "What SUP board volume is best for me?"
The short answer is: "It depends.  For beginners we recommend a volume of about twice your body weight."
Here is a longer explanation of our board volume recommendations:
First of all, you need to know your body weight into kg.
To convert from pounds to kg divide your weight by 2.2 (1 kg = 2.2 lbs)
Using myself as an example:  my weight is 195 lb. divided by 2.2= approx. 88 kg.
The metric system makes it easy to calculate lift created by volume as one kg is equals to the weight of one liter of water by definition (note that salt water is slightly denser so the same board will float slightly better in the ocean than in freshwater).   Interestingly most board dimensions are quoted in feet and inches but volume is always quoted in metric liters for this reason.
Basically: one liter of volume displaces one liter of water and therefore creates one kg of lift, so one liter of board volume will float one kg of weight.
For beginners, we recommend body weight in kg= liters x 2 (approximately) or about 176 liters volume for my weight of 88 kg.  This means that when I stand on the board, it will be pushed about half way under water to displace enough water to float my body weight plus equipment weight.   Please note that more volume will not necessarily make the board more stable.  Side to side stability is a result of the width of the board and the thickness of the rails and to a lesser degree the length of the board.  A thicker board can actually be less stable as the feet are higher off the water, raising the center of gravity.
For racing and touring you can go with a higher volume as thicker, high volume rails can add secondary stability to a narrower hull that has less resistance than a wider board.  In downwinders especially, high volume in the front of the board works well to keep the nose from plowing deep into the trough.
If high performance SUP surfing is your goal, as you improve you can gradually lower the volume of the boards you use since a lower volume board will generally surf better but will also be much harder to balance on and control, making low volume,high performance boards very difficult to learn on.  
Expert SUP surfers can use a board volume as low as their body weight plus board, paddle, clothing and gear weight plus a few liters extra, or about 100 Liters volume for my body weight.  At this volume the board will barely float when not moving.  Some pros even use boards that don't float them when standing still, they need the dynamic lift created from moving through the water to keep them afloat, the board will sink if they stop paddling, with the board volume in liters slightly less than their body weight plus board and equipment weight in kg.  
Once again:  The body weight times two is only a rough guide to recommended volume as the width and volume distribution of the board has a bigger impact on how stable the board will be.  Although we recommend buying a board that is challenging to balance on at first since your balance will quickly improve with practice, don't make the mistake of buying  a board that is too small for your skill level as that can be very frustrating.  The point is to have FUN!
SUP board volume
The 14' x 28" x 6" Bump Rider is a downwind board with 284 Liters of volume

Aloha, Robert Stehlik
www.blueplanetsurf.com

1 comment:

  1. That is great advice for the beginner paddle boarder.

    ReplyDelete

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