Volume vs rider weight

[Tecpartner]

Is there an equation for rider weight = suggested board volume? 

I weigh 200 lbs, paddle mostly flat water, need stability, and I like to race.  Does that indicate that I should be looking a boards of a particular volume or volume range?  Or does the volume requirement vary according to board design, panning vs displacement, length, width, hull shape, etc? 

[Easy Rider]

I don't know of a formula (never like math) but being 200 lbs. / paddling mostly flat water and liking to race - I will offer my thoughts.

I have paddled "race / flatwater" shapes ranging from a 23" wide Starboard NEW to a Jimmy Lewis Slice - and many, many in between.

The NEW was the least stable (due to width) and the Slice was like paddling a coffee table - a fast coffee table - very stable.

Volume will vary greatly between planing and displacement shapes - displacement ones being higher.

If you want to race / train / cover long distances on flat water - I would suggest to look for a displacement shape as they are easier to maintain a higher rate of speed.
With "our" weight I would also look for a higher volume board. 

Of course the key is to try and paddle as many as possible before you buy.

my 2¢

[1tuberider]

Volume requirements will be different for  various activities.  For surfing I use a 125 liter board and could probably be comfortable on 120 liters but it will cost me some waves.  I weigh close to 190 and use rubber.  This volume would be less than idea for cruising or racing. 

For racers its a whole new world and it is changing.  You will need to go big and try to have the same ratio that other winning racers use. 

One thing is for certain is that if you are new to paddling and somewhat out of shape, your weight is going to change depending on how hard you work out. 

PTWoody posted a formula and it was close for my surfing volume at the lower end. Many of the pop outs will have volume in sales literature.