Now this is a great tool to help you roughly work out the amount of volume in your board to suite you weight, ability and fitness. It's pretty simple really and is a great guide to what you might like in your board. Not a means to the end but a sign post along the way to help you find your magic board.
.34 - .36 for super fit, advanced performance surfers and pros
.36 - .38 above average, daily surfers
.38 - .42 average Joes and weekend warriors
.42 - .50 intermediates, beginners and those that want to dominate a line up