Thinking About The Hull In Catamaran Terms.

I mentioned earlier that T3 was a too floaty boaty so naturally the vision of it being useful as a hull for a catamaran crosses one's mind. It seems in the advertisements for catamarans that lightness is a wanted feature and understandably that would make sense when it comes to speed, handling and costs. What I would be interested to know is how lightness of a craft and specifically that of catamarans works in heavy weather sailing. If the craft is too light and sits high in the water and is very beamy, is she more subject to uncontrollable behaviour in a hoolie and more likely to tip than a heavier and more narrow boat? Old fashioned mono-hulls let to ride out a sea, a- hull, with warps, drogues, sea anchors etc -(http://bit.ly/1mr53Um),being heavy might, or could, be seen to settle better and be stronger than a lighter craft in such turmoil (breaking waves)
The original drift of much of my design was to produce a craft that would be efficient in moving through the water i.e. have no wake but also to be safe at sea and I think that having most of the buoyancy well forward would mean less likelihood of pitch poling, a danger for which one of the best options offered was a series drogue.
   By exactly the same token now confronted with a drogue the fine section aft of my hull(s) allows such sea surging from behind to 'part' and not push the hull forward at the same speed i.e. facilitate the purpose of the drogue. The hull pushed at or near the propagation speed of the wave form will be confronted with that which is seen to happen to the superficial part of the wave ie the change in direction as it crashes down. If the nose of the craft is prevented from sinking by forward buoyancy and if the sharp aft  parting the crest or top of the wave slows it down then the transit of the hull is more likely to be  horizontal or at most a flatish wave form.
However the issue of lightness persists as a worry for what I hope will be a 'folk' cat for ocean sailing. It is easy to see a very light cat being flipped by an irregular sea, let alone breaking waves, so one is immediately confronted with the prospect of having to make the craft heavier.
 A Keel For Safe Sailing In a Catamaran

Such keels as catamarans have tend to lie along each hull. A keel suspended from the platform or connections between the hulls might have some benefit. The keel may be pinned forward on its upper attachment ( in the plane of the lubber line) and so pivoted it can between all up or all down. It  can be boxed and lifted wholly up or down by perhaps some rack and pinion arrangement.forward to allow it to go up and down. Also the keel can be bi - pendulate, and fitted with some manner of a bulb that can be rapidly filled with sea water  and offer steadiness that way.

By the hinging of the keel in the lubber line at its upper attachment allows an adjustable bias in that it can be swung to windward easily - of course this stiffening of a catamaran might be folly under sail unlike a monohull but it is for toxic sea conditions that such a keel might reduce the likely-hood of tipping.
For light airs it can be lifted. For severe weather and concerns about the stability of the craft in large wave conditions the keel may be fitted with plates on each side hinged at or near its bottom edge such that they are free to fall away  a limited amount , to  ‘open up’ like an umbrella when sudden upsurges in the hulls occur. Such opening up would create a vertical drogue and resist wave and wind to topple the  boat. Downward motion of the hulls would tend to ‘close’ them and allow the hull to settle into the wave form  till the next upsurge opened them again. 

 I cannot quite decipher at what component of the wave form the boat is most vulnerable to tipping but it is most likely to be a mix of sliding on, up or down, the wave form and either stalling in speed, and so being overtaken, or falling off a crest or tripping into a trough. The wind situation makes things more complex.  

                            

As mentioned the bottom of keel might have a bulb that is hollow and that can be filled with water as necessary. In the water itself the only contribution weight wise will be that of this container. However the form, should it be fusiform or tear drop shape could have the plates mentioned above hinged along it lateral margin. Being round in section such plates would offer up a cusp concave uppermost and be ideal for acting as a vertical drogue.