"DSK" wrote
| Heck, a Soverel 33 will move at 4 or 5 knots in almost no wind at all,
| if well sailed. Maybe it's just making a ripple IYHO? Just a few
| weekends ago I watched a Kirie Elite 30-something (looked to be about 35
| feet) and a C&C 34+ tearing around the racecourse in winds of about 3
| knots and chop.


Capt. Mooron wrote:
The hell you say..... 4 or 5 kts in no wind!!! Okay Doug.... put down the
Jack Daniels and back away from the bar!! ;-)

No booze involved, not even American beer. The Soverel 33 is renowned as
a light-air speedster though, probably not a fair comparison. They make
a wake you can hear from 1/2 mile off on days when the wind is barely
enough to disturb cigarette smoke.


I have no experience with the Kirie Elite but I have been on a C&C 34 in
Vancouver. There is no way a C&C 34 can be described as "tearing around" at
3 knots... even with no chop!

It wasn't a C&C 34, it was the 34/36+ (or it might have been the 34/36
XL, not sure). Like this

http://www.yachtworld.com/core/listi...oat_id=1193723

The boat rates around 90 PHRF, in other words more than a minute per
mile faster than your boat.


| Yeah, there's that. But when the boat reaches some significant percent
| of hull speed, it's going to making waves not ripples.

Okay let's explore that point.... down wind with the wave train at let's
average it about a 2ft wave height and a 6 ft between crests. The boat is
doing lets say half an average hull speed [6kts]... on a dead downwind
run....so we'll call it 3 kts speed.

Huh??? That's not at all how it works. The wave-making resistance of a
hull increases with her speed in proportion to her Froude number, which
is a fairly complex derivative.

But let's make it simple... a hull with a 30' waterline has a "hull
speed" of 7.3 knots... meaning that at that speed, the crests of her
wave train will be 30' apart and she will require tremendous amounts of
increased applied power to go faster. At roughly 2/3 that speed, or 4.4
knots, she will be making waves of half her waterline length.

They may not be very high but the bow wave will certainly have a curl or
breaking crest, the stern wave probably will too (although it's a well
regarded feature of "fast" boats to leave low & clean stern waves).

Now bump the speed down a notch or two... only ripples? Sorry, you need
to pay closer attention... stop sneaking beer into the classroom and put
down that girly magazine! Anyway, depending on the hull of course,
there's no way a displacement boat is going to move at 1/2 or even 1/3
of her hull speed, when wave-making resistance is definitely a factor,
and make "only ripples." Small waves... OK but not ripples.

Jack Daniels? You can have my share... I've been hiding a bottle of
single malt in the desk...

Fresh Breezes- Doug King