Is there a maximum speed a sailing boat can travel?

Question

is there some relationship between area of sail and waterline length (which presumably affects drag)? or what other factors, if any are concerned? - assuming of course - just in case someone is tempted to mention it - no engine of any kind is in use!!

Answer 1

No, no theoretical limit. As said by another the normal maximum is 1.34 x sqrt(waterline length). however this only applies for conventional hull and sail layouts operating as displacement craft. Racing dingies go much faster as planing craft. I think the "30 knot sailboat" challenge was broken some time ago. Another fast craft is a windsurfer

Answer 2

A planing boat can go faster than hull speed.

A keel boat can go up to its hull speed.

Hull speed in knots=square root of the water line length

More sail area will make a boat go faster to a point, the hull speed, if a boat can not plane.

Wind is the next factor.

Do not forget currents.

Answer 3

Are you thinking of displacement hull speed? Displacement hull speed, simply put, is dictated by the waterline length. The longer it is the faster she'll go. When the vessel reaches 'hull speed' it will not go any faster unless a tremendous amount of extra "power" is available to climb the bow wave.

The formula for working out theoretical hull speed is:  1.34 times the square root of the waterline in feet

e.g. The square root of a waterline length of 25 feet = 5 x 1.34 = 6.7 knots.  Whereas something with a 100' waterline could reach up to 13.4 knots hull speed (depending on the sail area available), which is why the fast clippers of old were long and lean, with every inch of sail they could possibly hang out.

Answer 4

no. technology is miracle.impossible is nothing.

ADIDAS                                  lol

Answer 5

Max. Speed, well 2 speeds--->  Slow and Slower!!!!

Answer 6

I don't know of any theoretical maximum.  But new technology always comes along to help us to break through barriers we thought were impossible to break.

Yellow Pages Endeavor pushed the record to nearly 50knts with it's trifoil design.  Now some of the designs, such as the "Sail Rocket" have the sail way to leeward and angled so that any attempt by the rig to heal over actually acts to keep the hull flat, and therefore not lose power.  Sixty or Seventy knots may be possible in the right conditions.

Answer 7

Yes. But several factors can effect speed. As mentioned previously sail area, sail shape and waterline length are critical design elements that combine to propel a sail vessel to its maximum "hull speed". Other factors like hull shape and smoothness, overall weight, ballast (weight in the keel to keep boat upright) will have some effect on speed. There are usually design tradeoffs such as lots of sail area, skinny hull shape and light weight works well downwind but not so good upwind and vice versa.  Then there's monohulls vs. multihulls (catamarans). Monohulls are displacement boats meaning they must push water out of the way to move forward whereas multis sit mostly on top of the water and have far less drag from water resistance (and thus much faster). The exception is when a monohull in certain conditions like high winds and big waves can overcome surface tension with the water and actually surf on top dramatically increasing speed (dramatic is a relative term here).

All of this assumes the boat is travelling under wind/sail power in the water. Other scenarios exist whereas a sailboat can go considerably faster.

On a flatbed truck - 70-80 + mph.

Going over Victoria Fall - ~120mph

In the cargo bay of the space shuttle - 17,000 + mph

If launched out of the solar system with an occassional gravitational boost from a nearby planet speeds as high as 17km/sec could be reach (regardless of sail area or hull shape).

Hope this helps.

The Rockin W

Answer 8

The formula said above is correct however the fast round the world racers can touch 30knots. If you go to youtube and type "fast sailing" there are videos showing this.

Answer 9

Bardic is the most correct for a displacement hull....1.34X SR(waterline) for a THEORETICAL hull speed. Then he touches on the fact that extreme forces can push past this. He is again correct. Many of us avid Sailors have exceeded theoretical hull speed...at the risk of breaking our rigs or tearing sails or sinking/submerging...but...yes it is frequently done.

HYPOTHETICALLY...we have not yet seen the upper limit of SAIL DRIVEN SPEED. Technology is moving in leaps and bounds...there are rigid sails(yellowpages)...underwater foils lifting hulls out of the water(Moth class foilers)...all kinds of stuff...

Currently the 24 hour record is 27.8 knots by the 60' Trimaran Banque Populaire.

Out right records for speed which are usually a short distance sprint  go to:

Yellow Pages(a boat...sort of...hehe) at 46.52 kts and a Windsurfer at 48.7 kts.

For miles per hour multiply by 1.15.

So...nobody's broken 50 yet!

Hope this helps.

UPDATE:

regretfully, Science Teacher ...below ,is incorrect.

Hull Speed...this is THEORETICAL HULL SPEED...keyword: Theoretical....is  1.34 X Square Root of Waterline for a displacement hull coinciding with a trochoidal wave equal to waterline length. It is theoretical due to variables such as the waterline increasing as the boat heels over and waterline increasing as a hull aproaching it's upper limits of hull speed settles down into it's own wave trough...thus the waterline increases and the speed potential increases...up to and past 1.6 X S.R. Waterline...this continues theoretically until the vessel submarines(called: Sailing Under) to deck level (MAX WATERLINE) and comes to a halt due to water density and pops up if the hull is sealed or sinks if it continues... or pops up if the rig breaks(likely)...REAL On The Edge Sailing which few have the balls or repair money to do.

Emphatically....YES....a displacement hull can and will exceed theoretical hull speed. It's an imperfect formula given all variables

Answer 10

Ever hear sailing like the wind?  (as in at the same speed)

Answer 11

Depends how fast the wind is blowing and the strength/size of the sail and or the yacht.

Answer 12

A displacement hull speed max out at one wave length along waterline.  Anything faster will cause the boat to go uphill requiring an infinite about of power.  A sailboat is designed to use components to achieve max hull speed.  Any extra sail area or reduction of weight or other "improvements" are a waste since hull speed cannot be overcome without planning.

Planning hulls are a different story and max speed is more adjustable due to influences of weather, sea state, and boat technology.

Answer 13

There is clearly a relationship on the amount of energy put into the system (wind in the sail), and the amount of energy output from the system (power to propel the boat), but the variables are so vast and complex I think you'd need to be an A+ student in Fluid Dynamics to work it out accurately.

As well as Sail size, hull size you also have to consider the material the hull is made from, the shape of the sail, the drag caused by the rudder and keel, wind direction....