dimanche 22 novembre 2009

Sport Boat 18

So, now I have the drawings of the Sport Boat 18. A few data:
Length: 5.5 m
Wength at Water Line: 5.2 m
Draft (centerboard): 0.18 / 1.4 m
Draft (lifting keel): 0.46 / 1.57 m
Displacement: 663 kg
Ballast (centerboard / keel): 182 / 166 kg
Sail area: 22.4 m2
I really like the design of this litle boat. It looks very nice and must be very fast.
I went through several blogs of boat buiders and I have two fundamental questions that which I have difficulties to decide:
1- Lifting keel or Centerboard
2- Mast step on keel or mast step on deck
I would like to be able to take the boat in shallow water. Though it is not an absolute madatory thing, sailing in protected waters in the Houston area or at our place in Britany requires some ability to sail in shallow waters. The lifting keel system on this sport boat requires the main sail hallyard and the boom. So impossible to lift the kill at sea... It is a disadvantage in my eyes. However, this is a sport boat, if I start to question the fundamentals of a boat that is supposed to go fast, I should rather built a less extrem design, with a centerboard... I have looked a lot at the drawings, and I think I may be able to have some system install to lift the keel "partially" to meet my criteria. This may be adapted at a later stage. The other issue is trailer and launching from the trailer. Here again, I will need to look at how this can be done easily.
The other question regards the mast and it mainly concern the ability to rig up or rig down. I was more in favor of keeping the original design, but rigging up a mast 9 m long will be a difficult operation. I am looking at a carbon fiber mast to see if I can have it lighter than the alluminum mast. I have seen some of the SB18 under construction for a roof stepped mast. I do not really see how the mast can be rigged up with a hinge system on top of the roof. There are at least one interference with the cuddy top and one with the keel in its upper position.

After putting a lot of thoughts in all this, I am glad I come back to the original design of the boat and wont have to denature it.