Combination of power to weight ratio, skill, equipment and how it is set up..
For example early planing / acceleration.........
The fastest sprinters in the world out of the blocks over 100m are no light weights. They are athletes with superb power to weight ratio whereas most windsurfers over 90 kgs are simply fat.
Early planing is a key skill and too many people use their weight as an excuse to cover poor planing skills.