You might think that a 20 paddler boat could be faster than a 10 paddler,but you might be wrong. It does not really depend on how many people there are and how fast they paddle,but the actual mathematics behind the boat’s length and speed.
When a dragon boat moves ahead, the water is parted to allow the hull to move through it. A bow wave forms at the forward end of the hull (bow) and a similar one forms at the back (stern).
In less words, the speed that the boat goes doesn’t depend on the strength of the athletes inside the boat,but it actually depends on physics,calculation of the hull with the waves in the sea,and just simple math to answer your question.
Hull speed (in knots) = 1.34 x the square root of the waterline length (in feet)
Hull Speed (in m/sec) = 1.25 x the square root of the waterline length (in metres)