Lets have some details...

Some background on Volume calculations

What is the Guild factor? Well it turns out it is named after Whitney Guild, a surfer and scientist who was always interested in the relationship between a board's volume and the riders weight. In 2016 at a world tour event at Trestles he polled dozens of pro surfers about their weight and board volumes. The Guild factor is calculated by dividing volume (l) by weight (kg). It turned at that at pro level the factors were between 0.34 and 0,36 with most being 0.35! The Guild factor can help guide a surfer towards his ideal volume for a shortboard choice.

• Surfers at the top of their game 0.35
• Fit surfer, surfs regularly 0.36 - 0.38
• Weekend warrior 0.38 - 0.42
• Beginner 0.40 - 0.50
Note that its a guide only and many surfers will know what volume suites their style and ability. Also its not really relevant for longboard or mini-mal design as here you have lot more volume to play with due to the length of the board. Although the general rule of increasing a boards manoeuvrability along with it reduction in volume should always apply.