Gary wrote:
Okay, my turn again. I just googled you and see you may be a Nav Arch.

I've met Mr. Gatehouse and he is indeed a Naval Architect
and a good one.

So why don't you calculate the AVS?

Because (as he's been trying to tell you) it requires more data.


I am quite confident (and I am not a Nav Arch) that the boat will have a
better stability curve than is represented by the one posted.

Based on what? Your gut feeling?


If it doesn't, and it has an AVS of 110, I wouldn't touch it for
anything but coastal wandering.

Now here I agree. An LPOS (or AVS or whatever the TLA de
jour is) of 110 is far too low for any kind of rough weather
sailing even near coasts.

Going back a little bit

You also earlier said :
"- the ballast/displacement ratio is overly low, meaning a tender boat
with not enough stability "
A Nav Arch would know that initial stability is more than lots of
ballast.

Right, in fact the B/D ratio has little effect on *initial*
stability. But notice that in the original sentence, the
word "stability" was used, not the phrase "initial stability".

A boat can have very high initial stability and great sail
carrying power, but a very low LPOS (think scows or
catamarans). A very different type of boat can have low
initial stability and lots of ballast for lots of *reserve*
stability... ie steeply increasing righting moment at higher
angles of heel. A lot of old fashioned narrow heavy boats
are said to "heel only so far, and then stiffen up like a
rock." A boat like this can sail well at higher angles of
heel if the hull shape is fair & the rig/rudder are balanced
well. It can also have a very high LPOS yet be very
unsearthy.... think of the Twelve Meters.


... A raft has no ballast and is not tender. Wouldn't you say
that you are jumping to conclusions by not taking into account hull
form and the location of the ballast?

Umm, no... from the discussion so far, I'd say that you are
the one doing exactly that.

In other articles on the net, they also talk of the boat as "stiff"
and "stands up to her sails well".


That can easily be a function of her SA/D ratio as much as
hull form & ballast.

Fresh Breezes- Doug King