"Hull speed" is voodoo science
 

It is, of course, though many ignorant people will claim they read it in a
book, so it HAS to be true.

[the above to _try_ to instill *some* talk of boats on this silly ass ng]

"Hull speed" is voodoo science
 

Too late, Jax....
This NG has been taken over by limp-dicked lame-ass off topic posters that
have no life. I suggest finding a specific owners' group and hanging out
there.
It is sad that there is no moderation on this board. It USED to be a pretty
good source of information.



"JAXAshby" wrote in message
...
It is, of course, though many ignorant people will claim they read it in a
book, so it HAS to be true.

[the above to _try_ to instill *some* talk of boats on this silly ass ng]

"Hull speed" is voodoo science
 

Then why is the effect both predictable and
consistent?

When the results of an experiment conducted a million times are identical in
all regards, at what point can one draw a conclusion without being guilty of
voo doo science?

You could make a case that, under unique conditions, a vessel in displacement
mode
will attain speeds (in knots) greater than (sq rt of waterline expressed in
feet) X 1.3. You can make an accurate case that the multiplier for specific
hulls may vary between 1.2 and 1.4.

What cannot be argued is that beyond the calculated hull speed a vessel meets
the resistance of the bow wave, and must start climbing that wave (leave
displacement mode) in order to increase speed.

Exceptions prove the rule. If I observed that it is possible to have a rain
squall pass 20 yards away and stay perfectly dry, that would neither establish
that such a lucky break is a common occurence or that water isn't wet. :-)

"Hull speed" is voodoo science
 

Then why is the effect both predictable and
consistent?

it isn't. Most recreational sailboats made in the last 40 years will exceed
"hull speed" without any heavy lifting, and Hobie cats will go 3x "hull speed"
or more.

Some would argue that those hulls are planing, though plainly that is not the
case.

btw, mathematically the extra effort needed "to climb the bow wave" is zero at
"hull speed" and still doesn't amount to all that much at 2x "hull speed".

the THEORY is not theory at all, but oft repeated hearsay.

When the results of an experiment conducted a million times are identical in
all regards, at what point can one draw a conclusion without being guilty of
voo doo science?

You could make a case that, under unique conditions, a vessel in displacement
mode
will attain speeds (in knots) greater than (sq rt of waterline expressed in
feet) X 1.3. You can make an accurate case that the multiplier for specific
hulls may vary between 1.2 and 1.4.

What cannot be argued is that beyond the calculated hull speed a vessel meets
the resistance of the bow wave, and must start climbing that wave (leave
displacement mode) in order to increase speed.

Exceptions prove the rule. If I observed that it is possible to have a rain
squall pass 20 yards away and stay perfectly dry, that would neither
establish
that such a lucky break is a common occurence or that water isn't wet. :-)

"Hull speed" is voodoo science
 

it isn't. Most recreational sailboats made in the last 40 years will exceed
"hull speed" without any heavy lifting, and Hobie cats will go 3x "hull
speed"
or more.

Hobie "cat". The hull speed equation is intended to apply to monohulls in
displacement mode.


The arguable point is really the definition of displacement mode, not the
veracity of the hull speed theorem. IMO, a Hobie Cat is on plane....(hell,
sometimes airborne)..when it is making better than hull speed.

"Hull speed" is voodoo science
 

On 10 Apr 2004 17:22:35 GMT, (Gould 0738) wrote:

it isn't. Most recreational sailboats made in the last 40 years will exceed
"hull speed" without any heavy lifting, and Hobie cats will go 3x "hull
speed"
or more.

Hobie "cat". The hull speed equation is intended to apply to monohulls in
displacement mode.


The arguable point is really the definition of displacement mode, not the
veracity of the hull speed theorem. IMO, a Hobie Cat is on plane....(hell,
sometimes airborne)..when it is making better than hull speed.

A hobie cat doesn't plane. But it does break the hull speed "rule"
because that only applies to L/W ratios of around 3 or less. Hobie cats
are like in the 15-20 area.

Steve

"Hull speed" is voodoo science
 

IMO, a Hobie Cat is on plane....(hell,
sometimes airborne)..when it is making better than hull speed.

Hobies have DEEP Vee hulls, not possible to plane.

"Hull speed" is voodoo science
 

The arguable point is really the definition of displacement mode, not the
veracity of the hull speed theorem.

displacement means displacement, as in not rising above the natural float point
of the hull due to impact of water against the hull due to motion.

"Hull speed" is voodoo science
 

But it does break the hull speed "rule"

hull speed is a not a "rule" but rather an explanation that assumes both that a
boat *must* go over a wave rather than through it AND that boat speed is
governed by the speed of unconstrained water waves of infinite fetch.

"Hull speed" is voodoo science
 

Who cares what hull speed is? If you're having a good day on the boat,
what's the diff how fast you're having fun?

"JAXAshby" wrote in message
...
It is, of course, though many ignorant people will claim they read it in a
book, so it HAS to be true.

[the above to _try_ to instill *some* talk of boats on this silly ass ng]

"Hull speed" is voodoo science
 

Who cares what hull speed is?

The manatee police

If you're having a good day on the boat,
what's the diff how fast you're having fun?

$100

"Hull speed" is voodoo science
 

On 11 Apr 2004 15:11:46 GMT, (Greg) wrote:
Who cares what hull speed is?

The manatee police

If you're having a good day on the boat,
what's the diff how fast you're having fun?

$100

==================================

The manatee police are not allowed to run on plane unless in "hot
pursuit", therefore no one else should be on plane either.

It's about time we find some way to rein in the Fish and Wildlife
commission, as well as the Corps of Engineers. Both groups are out of
control in my opinion, and doing it with our tax dollars.

"Hull speed" is voodoo science
 

On 10 Apr 2004 13:45:52 GMT, (JAXAshby) wrote:
It is, of course, though many ignorant people will claim they read it in a
book, so it HAS to be true.

====================================

There are hull forms that are not bound by their own wave train, or
are bound to a lesser extent (such as long skinny hulls).

There are two primary sources of drag on a boat: Friction ( a function
of surface area and smoothness), and induced drag imparted from
converting motion into wave trains. At low speeds friction dominates
as the primary drag factor, and as speed increases wave making becomes
the dominant factor in a non-planing hull. For an average
displacement hull the tradional equation works fairly well at
identifying the approximate crossover point, where considerable extra
power is required to go any faster.

"Hull speed" is voodoo science
 

"Wayne.B" wrote in message
...
On 10 Apr 2004 13:45:52 GMT, (JAXAshby) wrote:
It is, of course, though many ignorant people will claim they read it in
a
book, so it HAS to be true.

====================================

There are hull forms that are not bound by their own wave train, or
are bound to a lesser extent (such as long skinny hulls).

There are two primary sources of drag on a boat: Friction ( a function
of surface area and smoothness), and induced drag imparted from
converting motion into wave trains. At low speeds friction dominates
as the primary drag factor, and as speed increases wave making becomes
the dominant factor in a non-planing hull. For an average
displacement hull the tradional equation works fairly well at
identifying the approximate crossover point, where considerable extra
power is required to go any faster.


Thanks Wayne.

Mark Browne

"Hull speed" is voodoo science
 

"Greg" wrote in message
...
Who cares what hull speed is?

The manatee police

If you're having a good day on the boat,
what's the diff how fast you're having fun?

$100

What method do they use to measure your speed?

"Hull speed" is voodoo science
 

On Sun, 11 Apr 2004 16:43:58 GMT, "Mark Browne"
wrote:

Thanks Wayne.
========================

You're quite welcome. Hopefully I didn't belabor the obvious.

"Hull speed" is voodoo science
 

IMO, a Hobie Cat is on plane....(hell,
sometimes airborne)..when it is making better than hull speed.

Hobies have DEEP Vee hulls, not possible to plane.


Normally laden, all but a few inches of that
"Deep Vee" is above the waterline.

What's the effective draft of a Hobie Cat, in inches?

One could make a case that the boat is always, (effectively) on plane at least
as easily as a case that it cannot plane at all.

http://www.hobiecat.com/sailing/index.html

The exceptions prove the rule, as always.

( OT ) LIES! LIES! LIES! DAMNED LIES!
 

The White House this weekend released a section of the classified August
6, 2001 Presidential Daily Briefing
(http://www.centredaily.com/mld/centr...ws/8409007.htm) (PDB), which
explicitly warned President Bush of an imminent al Qaeda attack inside the
United States. The document contradicts President Bush's own denials, and
raises the question of whether National Security Adviser Condoleezza Rice
lied under oath last week in describing the memo's contents before the
bipartisan 9/11 Commission. The President "said yesterday that a memo did
not contain enough specific threat information
(http://www.washingtonpost.com/wp-dyn...2004Apr11.html) " with
Bush claiming "the PDB was no indication of a terrorist threat" because it
supposedly " said nothing about an attack on America
(http://www.whitehouse.gov/news/relea.../20040411.html) ...was not
a time and place of an attack" specified. But as the NYT notes, the PDB "
spells out the who, hints at the what and points toward the where
(http://www.iht.com/articles/514272.html) of the terrorist attacks on New
York and Washington that followed 36 days later." CNN Political Analyst
(and AEI scholar) Bill Schneider said the PDB revelations " could be
seriously damaging
(http://us.cnn.com/2004/ALLPOLITICS/0...tsc.schneider/) . What this says
is, the White House knew what bin Laden was capable of planning, where he
intended to do it, which was New York or Washington, D.C., and how he was
going to do it."



LYING UNDER OATH -- PDB REFUTES RICE'S SWORN TESTIMONY: In her testimony
under oath before the 9/11 Commission last week, Rice said the August 6th
PDB "was historical information based on old reporting. There was no new
threat information. And it did not, in fact, warn of any coming attacks
(http://www.nytimes.com/2004/04/08/politics/08RICE-
TEXT.html?pagewanted=print&position=) inside the United States." But the
PDB contained very current and specific information
(http://www.washingtonpost.com/wp-dyn...2004Apr10.html) about
ongoing investigations and threats -- a direct contradiction of Rice's
testimony (http://www.sfgate.com/cgi-
bin/article.cgi?file=/c/a/2004/04/10/MNG3G638001.DTL) . The PDB said there
were "patterns of suspicious activity in this country consistent with
preparations for hijackings or other types of attacks, including recent
surveillance of federal buildings in New York...The FBI is conducting
approximately 70 full field investigations throughout the US that it
considers Bin Ladin-related" including one following leads about "Bin Ladin
supporters in the U.S. planning attacks with explosives." American Progress
reports the truth behind Rice's testimony.
(http://www.americanprogress.org/site...RJ8OVF&b=44918)



DISHONESTY -- STILL SAYING HE REQUESTED THE BRIEFING: The President
yesterday insisted that he personally requested the August 6 intelligence
briefing (http://www.whitehouse.gov/news/relea.../20040411.html)
because he was so concerned about terrorism, saying "I asked the
intelligence agency to analyze the data to tell me whether or not we faced
a threat internally...That's what the PDB request was." But according to
the CIA, the briefing " was not requested by President Bush
(http://www.washingtonpost.com/wp-dyn...04Mar24_2.html) ."
As commissioner Richard Ben-Veniste disclosed, "the CIA informed the panel
that the author of the briefing does not recall such a request from Bush
and that the idea to compile the briefing came from within the CIA."



NEGLIGENCE -- LOAFING WHILE SUPPOSEDLY "AT BATTLE STATIONS": The WP
explored the Bush Administration's claims that " The President of the
United States had us at battle stations (http://www.washingtonpost.com/wp-
dyn/articles/A2676-2004Apr10.html) " during the summer of 2001. But "if top
officials were at battle stations, there was no sign of it on the surface.
Bush spent most of August 2001 on his ranch" -- taking one of the longest
Presidential vacations in White House history
(http://www.usatoday.com/news/washing...01-08-03-bush-
vacation.htm) . One former Bush aide "who remains close to the White House
said the use of the term 'battle stations' by Rice was an overstatement."
And as an American Progress backgrounder
(http://www.americanprogress.org/atf/...A2B-43C7-A521-
5D6FF2E06E03%7d/timeline.pdf) shows, the President did not appear to
change his schedule at all from the month-long regimen of golf, running,
and cookouts. The Minneapolis Star Tribune editorial board said the
President's pre-9/11 conduct displayed " a criminal lack of interest in
trying to prevent an attack
(http://www.startribune.com/stories/561/4712842.html) on the United States
that the administration had strong reason to expect" adding that "almost
nothing of a defensive nature was done to guard against -- to prevent --
the horrific spectacle that unfolded on Sept. 11."



--
Jim

( OT ) LIES! LIES! LIES! DAMNED LIES!
 

Maybe they did know the attack was in DC and NYC so that was where all the cops
went. The planes were hijacked in Boston.

( OT ) LIES! LIES! LIES! DAMNED LIES!
 

On Mon, 12 Apr 2004 17:34:03 GMT, Jim wrote:


The White House this weekend released a section of the classified August
6, 2001 Presidential Daily Briefing

Do you really need 12-15 different news sources to tell you what was in the PDB
of 6 August. Here it is, just read it. Where does it give the who, what, when,
where?

Bin Ladin Determined to Strike in US

Clandestine, foreign government, and media reports indicate Bin Ladin since
1997' has wanted to conduct terrorist attacks in the US. Bin Ladin implied in US
television interviews in 1997 and 1998 that his followers would follow the
example of World Trade Center bomber Ramzi Yousef and "bring the fighting to
America."

After US missile strikes on his base in Afghanistan in 1998, Bin Ladin told
followers he wanted to retaliate in Washington, according to a [deleted text]
service. An Egyptian Islamic Jihad (EIJ) operative told an [deleted text]
service at the same time that Bin Ladin was planning to exploit the operative's
access to the US to mount a terrorist strike.

The millennium plotting in Canada in 1999 may have been part of Bin Ladin's
first serious attempt to implement a terrorist strike in the US. Convicted
plotter Ahmed Ressam has told the FBI that he conceived the idea to attack Los
Angeles International Airport himself, but that Bin Ladin lieutenant Abu
Zubaydah encouraged him and helped facilitate the operation. Ressam also said
that in 1998 Abu Zubaydah was planning his own US attack.

Ressam says Bin Ladin was aware of the Los Angeles operation.

Although Bin Ladin has not succeeded, his attacks against the US Embassies in
Kenya and Tanzania in 1998 demonstrate that he prepares operations years in
advance and is not deterred by setbacks. Bin Ladin associates surveilled our
Embassies in Nairobi and Dar es Salaam as early as 1993, and some members of the
Nairobi cell planning the bombings were arrested and deported in 1997.

Al-Qa'ida members — including some who are US citizens — have resided in or
traveled to the US for years, and the group apparently maintains a support
structure that could aid attacks. Two al-Qa'ida members found guilty in the
conspiracy to bomb our Embassies in East Africa were US citizens, and a senior
EIJ member lived in California in the mid-1990s.

A clandestine source said in 1998 that a Bin Ladin cell in New York was
recruiting Muslim-American youth for attacks.

We have not been able to corroborate some of the more sensational threat
reporting, such as that from a [deleted text] service in 1998 saying that Bin
Ladin wanted to hijack a US aircraft to gain the release of "Blind Shaykh"
'Umar' Abd aI-Rahman and other US-held extremists.

Nevertheless, FBI information since that time indicates patterns of suspicious
activity in this country consistent with preparations for hijackings or other
types of attacks, including recent surveillance of federal buildings in New
York.

The FBI is conducting approximately 70 full field investigations throughout the
US that it considers Bin Ladin-related. CIA and the FBI are investigating a call
to our Embassy in the UAE in May saying that a group of Bin Ladin supporters was
in the US planning attacks
with explosives.
*****************************************

John H

On the 'Poco Loco' out of Deale, MD
on the beautiful Chesapeake Bay!

Dealing With Defective Defectors
 

http://slate.msn.com/id/2098558/

Extract

CBS's 60 Minutes proved the exception last month when it disowned part of a
two-year-old story. On March 3, 2002, the newsmagazine profiled Ahmad
Chalabi and his Iraqi National Congress.
--
Jim

"Hull speed" is voodoo science
 

utter lack of understanding on your part gould. you are trying to force fit
garbage science into a unified theory of the universe.

IMO, a Hobie Cat is on plane....(hell,
sometimes airborne)..when it is making better than hull speed.

Hobies have DEEP Vee hulls, not possible to plane.


Normally laden, all but a few inches of that
"Deep Vee" is above the waterline.

What's the effective draft of a Hobie Cat, in inches?

One could make a case that the boat is always, (effectively) on plane at
least
as easily as a case that it cannot plane at all.

http://www.hobiecat.com/sailing/index.html

The exceptions prove the rule, as always.

"Hull speed" is voodoo science
 

one the hull goes through the wave, what prevents another from forming
just ahead? .... or does one? Is this like breaking the sound
barrier, where one leaves compressability issues behind?

that has *nothing* to do with "climbing the bow wave.

"Hull speed" is voodoo science
 

ah, duh. makes sense to me. doesn't it?

[grin]

Who cares what hull speed is? If you're having a good day on the boat,
what's the diff how fast you're having fun?

"JAXAshby" wrote in message
...
It is, of course, though many ignorant people will claim they read it in a
book, so it HAS to be true.

[the above to _try_ to instill *some* talk of boats on this silly ass ng]

"Hull speed" is voodoo science
 

There are hull forms that are not bound by their own wave train, or
are bound to a lesser extent (such as long skinny hulls).

no hull is "bound by its own wave train". none.

"Hull speed" is voodoo science
 

induced drag imparted from
converting motion into wave trains.

bull. that is not what induced drag is at all. check your terms.

"Hull speed" is voodoo science
 

as speed increases wave making becomes
the dominant factor in a non-planing hull.

bull, induced drag goes up at the cube of boat speed and has nothing to do with
waves at all.

"Hull speed" is voodoo science
 

For an average
displacement hull the tradional equation works fairly well at
identifying the approximate crossover point, where considerable extra
power is required to go any faster.

bull. most every recreational sailboat made in the last 40 years regularly and
rather easily exceeds the speed predicted by "the tradional equation".

"Hull speed" is voodoo science
 

for what, mark? for what?

Thanks Wayne.

Mark Browne

"Hull speed" is voodoo science
 

You're quite welcome. Hopefully I didn't belabor the obvious.


no, you didn't belabor the obvious. you did belabored erroneous, voo-doo
science as written by writers plagarizing other writers who plagarized others
who took to heart a silly, yet scientific sounding, explanation given to 19th
century British naval brass who couldn't understand why doubling the power to a
boat of the time didn't double the speed of the boat. the brit brass dumbly
nodded their heads and proclaimed to the Queen that they had the fastest boats
on the planet.

"Hull speed" is voodoo science
 

Is it your position that drag on the hull does not increase with
speed?

the induced drag on a hull goes up at the cube of speed and has nothing to do
with "climbing the bow wave". A cubic function is mathematically well behaved,
meaning nothing untoward happens anywhere on the curve.

"Hull speed" is voodoo science
 

comments interspersed.

Is it your position that drag on the hull does not increase with
speed?

the induced drag on a hull goes up at the cube of speed and has nothing to
do
with "climbing the bow wave". A cubic function is mathematically well
behaved,
meaning nothing untoward happens anywhere on the curve.

Then it follows from observation of this well behaved curve that,
given sufficient horsepower, a displacement hull is not limited in
speed.

this is true, though a cube function explodes in magnitude. But it does so in
a mathematically well-behaved way.


Or perhaps, to put it another way, the wave system created by the hull
passing through the water is not limited in speed, either.

specious arguement unrelated to the discussion.


Thus, given the mathematical example, both the hull and the associated
wave system could travel at, say, 45 MPH for a 25 foot boat ....
assuming adequate available horsepower.

see above


--



Grady-White Gulfstream, out of Southport, NC.

http://myworkshop.idleplay.net/cavern/ Homepage
http://www.southharbourvillageinn.com/directions.asp Where Southport,NC
is located.
http://www.southharbourvillageinn.linksysnet.com Real Time Pictures
at My Marina
http://www.thebayguide.com/rec.boats Rec.boats at
Lee Yeaton's Bayguide

"Hull speed" is voodoo science
 

could travel at, say, 45 MPH for a 25 foot boat ....
assuming adequate available horsepower.

**assuming** the 25 foot boat takes 1 hp to go 1 mph, then it would take 4 hp
to go 2 mph: 16 hp to go 4 mph; 64 hp to go 8 mph; 256 hp to go 16 mph; 1024 hp
to 32 mph; ~2000 hp to 45 mph.

note, this is the hp needed to overcome induced drag at greater speeds. note
also that there is no break point anywhere on the hp vs speed curve due to
"climbing the bow wave"

note-2, **if** a boat were REQUIRED "to climb the bow wave" rather than slice
through wave, the extra hp needed is only about 40% more at 2x hull speed than
is needed just to overcome induced drag. Even at 4x hull speed, the increase
due to the alleged requirement "to climb the bow wave" not huge compared the hp
needed to overcome induced drag.

In fact, **if** the boat were REQUIRED "to climb the bow wave" (it is not
required) the extra hp needed only starts to become truly substantial only when
boat speed starts to get VERY high, i.e. two or three or four orders of
magnitude (that's 100x, 1000x 10,000x) greater than hull speed.

it ain't "climbing the bow wave" that limits the speed of a boat.

"Hull speed" is voodoo science
 

Is it your position that drag on the hull does not increase with
speed?


JAXAshby wrote:
the induced drag on a hull

A hull doesn't usually have "induced drag." That is a term specific to
the behavior of foils.

... goes up at the cube of speed

wrong

... and has nothing to do
with "climbing the bow wave".

wrong again, at least in practical terms.

Wow, a hull speed discussion with Jax and I almost missed it!




... A cubic function is mathematically well behaved,
meaning nothing untoward happens anywhere on the curve.

Can I quote you on that?



Gene Kearns wrote:
Then it follows from observation of this well behaved curve that,
given sufficient horsepower, a displacement hull is not limited in
speed.

If other factors are not considered, true. But what hull can withstand
the force generated by the nearly infinite horsepower that is required
for marginal increase in speed? Is the hull's reserve bouyancy
sufficient to keep it above the water level of it's own exaggerated wave
train at higher speeds?


Or perhaps, to put it another way, the wave system created by the hull
passing through the water is not limited in speed, either.

Actually, it is. Waves can only travel so fast... this is a physical
property of the fluid that forms the wave.


Thus, given the mathematical example, both the hull and the associated
wave system could travel at, say, 45 MPH for a 25 foot boat ....
assuming adequate available horsepower.

Probably yes.

The difference between "planing" and "displacement" is one of the most
misunderstood things about boats. But very few people can be as
consistently wrong, or as funny, as Jax. He was gifted even as a child.

DSK

"Hull speed" is voodoo science
 

a.) bull****
b.) bull****
c.) bull****
d.) you miss most things in life.

Is it your position that drag on the hull does not increase with
speed?


JAXAshby wrote:
the induced drag on a hull

A hull doesn't usually have "induced drag." That is a term specific to
the behavior of foils.

... goes up at the cube of speed

wrong

... and has nothing to do
with "climbing the bow wave".

wrong again, at least in practical terms.

Wow, a hull speed discussion with Jax and I almost missed it!




... A cubic function is mathematically well behaved,
meaning nothing untoward happens anywhere on the curve.

Can I quote you on that?



Gene Kearns wrote:
Then it follows from observation of this well behaved curve that,
given sufficient horsepower, a displacement hull is not limited in
speed.

If other factors are not considered, true. But what hull can withstand
the force generated by the nearly infinite horsepower that is required
for marginal increase in speed? Is the hull's reserve bouyancy
sufficient to keep it above the water level of it's own exaggerated wave
train at higher speeds?


Or perhaps, to put it another way, the wave system created by the hull
passing through the water is not limited in speed, either.

Actually, it is. Waves can only travel so fast... this is a physical
property of the fluid that forms the wave.


Thus, given the mathematical example, both the hull and the associated
wave system could travel at, say, 45 MPH for a 25 foot boat ....
assuming adequate available horsepower.

Probably yes.

The difference between "planing" and "displacement" is one of the most
misunderstood things about boats. But very few people can be as
consistently wrong, or as funny, as Jax. He was gifted even as a child.

DSK

"Hull speed" is voodoo science
 

Although you are a block head, you are not as well behaved a cube function.

JAXAshby wrote:
a.) bull****
b.) bull****
c.) bull****
d.) you miss most things in life.

"Hull speed" is voodoo science
 

I'd be very interested in hearing your explaination of how "induced drag"
occurs when moving a hull through water at or below hull speed.(or air for
that matter). I have a pretty good understanding of induced drag when moving
keels and rudders...hulls OTOH, I don't know about. Also, every formula that
I've looked at for calculating the induced drag coefficient is a square
function, not cube. But I'm always willing to learn when presented with a
valid argument based on facts.

"JAXAshby" wrote in message
...

the induced drag on a hull goes up at the cube of speed and has nothing to
do
with "climbing the bow wave". A cubic function is mathematically well
behaved,
meaning nothing untoward happens anywhere on the curve.

"Hull speed" is voodoo science
 

qweaver, listen up. "induced" drag does indeed go up by the square of the
speed. *however* the ***horse power*** required goes up at the sum of the
induced drag plus the additional hp needed for increased speed. in other words,
hp needed goes up at the cube of speed.

of course, *you* are not required to believe anything you don't understand, or
don't wish to "when presented with a valid arguement based on facts".