wrote:
Gary wrote:

wrote:

I've got this report from Tayana for the Vancouver 460 Pilot
but don't know how good it is.

http://tayana46.tripod.com/safety.htm

If anybody can understand the Righting Arms vs Heel curve and
the numbers on this web page please let me know.

The consensus here seems to be that Tayanas in general are safer
bluewater yachts but I don't know if the pilothouse makes this
Vancouver 460 less stable or more dangerous.

Thanks again for your help.


The pilothouse likely won't make the boat any less stable than the boat
without it. In fact, if the boat was to ever go blow 90 degrees the
pilothouse would add to the righting moment with its' great buoyancy.

The Righting Arm vs Heel Curve is quite telling and disturbing. Ideally
the area under the curve when the boat is upside down is significantly
smaller than the area under the curve when the boat is right side up.
In this instance the area under the curve is fairly large indicating
that the boat is quite stable upside down. In fact it is almost as
stable upside down as it is right side up. Not great.

According to this curve the Angle of Vanishing Stability (AVS) is about
110 degrees. That is unsatisfactory. Most offshore boats are designed
with an AVS in excess of 120 degrees.

After looking around the net I would have to say that this graph of RA
vs HC is wrong. Tayana claims an AVS of 0 degrees which would make
sense given the buoyancy of the pilothouse (Provided the windows don't
break).

Check out: http://www.tayanayachts.com.tw/V460.htm

I would rather the Tayana over the Beneteau.


As mentioned in the other thread, the numbers and curve on my
web site were given to me by Tayana.

With the pilothouse filled with air I would also expect this boat
to have no stable state upside down. But in this case shouldn't
the AVS be 180 degrees instead of 0 ?
It doesn't really matter how you say it, as long as we both understand
that the boat will not stay upside down.