Visionarry figures come in pretty close to that of the harry.
What also is important is the amount of sail that the boat can carry
before tipping, and the Harrys do very well at that. This is talked
about in the visionarry design part of the harryproa website,
Robert
--- In harryproa@..., "robertbiegler"
<Robert.Biegler@s...> wrote:
>
> --- In harryproa@..., "oceanplodder2003"
> <dana-tenacity@u...> wrote:
> > Just been reading an article on these, seems 1.9 and above is a
fast
> > boat, do we know what the no. is for Harry?
>
> The Bruce number is simply the square root of sail area divided by
the
> cube root of displacement. The numbers caclulated from metric or
> imterial units differ by about a factor 4. For Harry, calculated
from
> sail area and displacement in metric units and racing trim (empty
> weight plus two crew) it's 7.02, calculated from imperial units
it's
> 1.76. At designed cruising displacement, the numbers are 6.12 from
> metric units and 1.53 from imperial units.
>
> As for a Bruce number of 1.9 or above, that's for pretty extreme
> racers requiring a lot of attention and skill. Ellen Macarthur's
B&Q
> comes in at 7.95 in mteric or 1.99 in imperial. Fujifilm, one of
the
> ORMA 60 trimarans is at 9.52 or 2.39. That's the kind of boat
which
> is fully powered up in 8 knots of wind. Most monohull cruisers
come
> in at 4 to 5 or 1 to 1.25, reasonably fast multihull cruisers at
about
> 6 or 1.5. Personally, I wouldn't recommend much more than that
unless
> you either sail a boat small enough that a capsize is a mere
nuisance,
> or you are an adrenalin addict with exceptional skill and attention
> span and you can afford the cost of the occasional salvage. Though
if
> you do crave that sort of excitement, I am sure Rob can provide it.
>
> Regards
>
> Robert Biegler
>