Genesis, if you click in the white block with your right mouse button, where it says the things you want to know, you can read in the explanation of that.
Hull speed is the max speed a hull (displacement hull only), (not applicable to statre of the art planing hulls), can achieve, and its calculated based on lenght at the water line. The longer the LWL the faster that boat can go.
The formula is HS = (LWL) Power 1/2 X 1.34
It only works for boats that do not plane in the water.
Basically when a boat moves in the water it creates a wave that restriscts the increase of its speed. It will be trapeed in it own water displaced water.
When moving, a boat will create a wave in the bow and another wave in the rear, in the stern. When the boat gets near its hull speed the two waves will combine to make only one wave.
What happens is that the boat will be unable to go "over" its own wave, no matter how hard it is pushed, the wave just gets bigger and he can't go any faster.
That is when fine very good looking excellent nice sailboats like yours trully come to play...these very high effecient modern good looking hulls, called planing hulls, due to their flat appearance and low drag, are able to start "surfing" over the surface of the water, and once they do that, they start planing over the wave, then, no longer under the influence of the wave, they can accelerate further.....and fly as fast as the wind!!
Was that clear?
The photo bellow shows a boat that is going so fast the waves are really big. At this point, the Spi was hoisted and the boat starts to accelerate. The boat at this stage is not surfing yet. here is bellow 9 knots.
Once it starts surfing, the wave effect no longer apply all you have is a smooth wake, here it is going at around 17 knots.
I'll see if I have more