"Hull Speed" as commonly published is only a measure of the waterline length, and thus
will be the same for all boats with the same waterline. It is not a measure of how easily
driven the hull form is, or how much power the sails will generate. It simply an
indication of the speed at which a traditional displacement hull will "top out." It has
little bearing on modern planing boats, or boats with long, narrow hulls. Even
traditional displacement boats will exceed their hull speed through design "tricks" such
as long overhangs which increase the waterline at speed.

Other measures, such as SA/Disp give a better indication of speed potential. For the
Seawind, SA/Disp is a low 14.67; the Pearson 35 is 15.38; the Tartans are in the 16-17
range; the Bristol is 16.2. And this is really only a measure of whether the boat
carries enough sail to drive the boat in moderate conditions.

Another useful measure is the PHRF rating, which is a very high (that is, slow) 240 for
the Seawind. Many 32 foot boats are in the 180 range, whereas a performance oriented boat
could be around 120 or lower. Since this is a racing handicap, it is biased toward "round
the buoys" sailing, which isn't always relevant to a cruiser, but it is still a useful
number.



--
-jeff www.sv-loki.com
"I wish to have no connection with any ship that does not sail fast; for I intend to go in
harms way." - John Paul Jones


sail_south wrote:
Hello All,

Please help me out, I've read and been told that the Allied is a VERY
slow boat. But, when I check other boats that I'm interested in, they

all seem to have about the same hull speed. Am I missing something?

Examples:

allied - 6.8
tartan 34 - 6.7
pearson 35 - 6.7
bristol 35 - 6.4
tartan 37 - 7.3

Of all these boats the allied is most sea kindly in motion comfort and
has the lowest capzize numbers?

Is the allied not able to achieve hull speed?

Thanks for the help.

(I got the numbers from- http://www.image-ination.com/sailcalc.html


Hope to be sailing south in something soon.

Jim