Originally Posted by bobperry
How does the bathtub type do in light and moderate air. I see a hull with a lot of wetted surface? I don't know who is sailing what. I need some coaching on this.
First let me tell you about David Raison, an extraordinaire character, a NA and a mini racer that believed so much in this project (that for most was a joke) that he sold is house to build the boat.
Let me tell you also that this is not the kind of guy that has an idea, went for it and got lucky. This is the kind of guy that made exhaustive studies with CFD before building the boat. He says that the hull worked exactly as it has supposed to work...he said also that when he took the boat out of the mold and had a good look at it he was apprehensive and thought to himself "I hope those studies prove right"
Curiously he says that the idea come from the Optimists and also from Caravels. In fact I had read in transcriptions of old naval documents (XV/XVI centuries) that they believed that a ship should have a well rounded bow.
Regarding performance nothing better to hear what he says about the boat:
He says that the boat works very well in almost all conditions and says also that there is a price for that: less comfort (sea motion) and structural difficulties.
In fact he took several years to manage to sort out those structure problems due to the increased sail power and probably also due to the increased pounding the boat takes in heavy seas. When he arrived on the last transat (that he won) he said in an interview that in some conditions he had a lot of trouble to preserve the boat in heavy seas and that had been afraid in some occasions.
He says that the conditions were the boat has a bigger advantage is reaching were the increase in speed can be over 15%. On the other sailing positions the gains are not as big and on light winds, specially with choppy conditions the boat is less performat than traditional ones.
I thought that with waves upwind the boat would be slower but it seems that not with all types of waves, as we could saw on this race.
I thought also that the boat would point less well than the other minis and that is not simply true at least with flat water.
They have made also testing in several occasions with other top minis and the results were clear, even in what regards to go faster upwind close to the wind in flat water and medium winds.
Have a look:
David Raison, Magnum : l'arme absolue por voilesetvoiliers