Re: [Paddlewise] paddlefloat photo

Michael Daly wrote: 
> From: "Peter Rathmann" <prathman_at_attbi.com>
> > To the extent that [internal sponsons] keep interior water from sloshing to the
> > sides of the boat they will certainly aid the stability relative to a
> > boat of the same shape that lacks internal sponsons.
> 
> True, but the effect may be small and only kick in a higher angles of heel.
> I'm not sure that the effect would be enough to brag about.

The size of the effect would depend on the particular design and could
vary from very small to large.  Before you argued that there was no
effect at all of internal sponsons on stability of a flooded boat and my
post was primarily to point out that there was indeed such an effect.  
> Having
> deliberately flooded a couple of kayak in a pool, I know that the reduction
> of stability is tremendous and I don't think a sponson's several liters of
> volume (compared to the, say 150+ liter cockpit volume) is going to make a
> big enough difference.

Who said they were only a few liters?  This is again a question of the
specific design and internal sponsons that occupy all the space on the
sides of a wide cockpit could easily constitute a high percentage of the
total original (unsponsoned) cockpit volume.
> 
> A snug sea sock may be the alternative.  There the volume is constrained and
> if the sock can't slide sideways, the water is better constrained.

Again, there is no reason why the internal sponsons couldn't occupy all
the space that is outside the seasock.  I would expect the sponson
approach would actually be easier to make in a way that would constrain
water movement, but that is also a question of design details.  If you
believe that a properly fitted sea sock could add to stability in a
flooded boat, then similarly fitted internal
sponsons/bulkheads/'whatever you want to call them' can certainly do the
same thing. As you said before, the water can't tell the difference.

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