0
This is a way to get a general hull speed - other factors (such as weight, beam - width of the boat, etc.) can affect this calculation.
Measure the craft's waterline length in feet.
Take the square root of the waterline length.
Multiply the square root of the length by 1.34. This number is the hull speed for your vessel as measured in knots.
Double check your answer. The equation written out looks like:
v = 1.34 (square root of LWL)
Where v is the speed of the vessel in knots, and LWL is the length of the craft's waterline in feet.
Triple-check your answer by plugging in the information on a hull speed calculator, such as the one on sailing USA's website.
Wiki User
∙ 13y ago
Add your answer:
Earn +20 pts
What is the maximum speed of a sailboat?
Maximum Speed of a Single-Hull Displacement Boat Hull Speed = 1.34 x the square root of the LWL LWL: length of the hull at the waterline. Please note: this is the theoretical maximum speed of a displacement monohull and does not take into account the following criteria: 1. Hull Design - each hull's contours will effect the laminar flow, that is how smoothly and effortlessly the water flows over it. Every design has a certain co-efficient of drag, and depending on the hull, more or less inherent and induced drag. 2. Displacement - just like with a car, the lighter you make a boat, the faster you can make it go. 3. Sail Area/Displacement Ratio - this is a bit like the power/weight ratio in a car. Since the sails are pushing the boat through the water, the heavier the boat, the larger the sails will have to be in order to take maximum advantage of the hull speed formula. If two vessels have the same hull design and the same sail area, the one with the lower displacement will be the faster vessel. 4. Type of Keel - there are two main types of keels, full and fin. Full means that the keel runs the length of the underside of the hull and fin is just what it sounds like - a fin placed roughly amidships. Depending on the weight and shape of the keel the boat will move faster or slower. If you want to know the hull speed of a particular make and model of boat, see if you can find a polar diagram. Polar diagrams, or plots show the speed of the hull at various points of sail and with various wind velocities.
Is there a unsafe speed for a sail boat?
Monohulls have a maximum hull speed that they will simply not sail faster than - while the hull speed of a particular vessel may be slightly more or less than the estimated hull speed, based on unique characteristics of the hull, this number is still, essentially, a constant. The following formula is an estimate of that hull speed. Hull Speed = 1.34 * (LWL)1/2 where LWL is the length of the hull at the waterline. The hull speed is, we should note, the speed *through the water* - ie., if you are travelling down a wave or with a current, your speed relative to shore may be higher. A multihull boat - like a catamaran or a trimaran - is most often exempt from this limitation because they are non-displacement or "planing" hulls: that is to say, that as a catamaran goes faster, it lifts farther out of the water. At very high speeds, this can result in instability and control issues, though with larger cats it's fairly uncommon or them to actually tip over. The maximum safe speed, however, is largely one of conditions: sea state, wind speed, and the experience of the captain and crew. To answer your question another way: there's an unsafe speed for *anything* - depending on conditions and surrounding obstacles - but the dangers involved in sailing are mostly not associated with exceeding any sort of imaginary speed limit.
How fast generally will a 25 ft sailboat travel motoring with 9.9 hp Johnson outboard?
maximum speed (hull speed) with a displacement hull with a 25ft waterline would be 6.75 knots or 7.76 mph. You 25 ft boat may have a shorter waterline, thus be a little slower.
What does hull speed mean?
Hull speed is the theoretical limit of a sailcraft's speed. It can be approximated by the following formula: 1.34 * SQRT(LWL), where LWL is the length of the waterline, in feet. As a small vessel approaches its hull speed, the hull begins to climb its own bow wave. The faster the vessel tries to go, the more difficult climbing the bow wave becomes. Eventually, should the hull type permit it, the hull will begin to hydroplane (skimming across the water.
What is the hull speed for a Catalina 22 sailboat?
A rough estimate of hull speed in knots is 1.34 times the square root of the length at the waterline in feet. The Catalina 22 has a 19 foot waterline, leading to an estimated hull speed of 5.8 knots
What is a speed boat hull made from?
fiberclass
What is a single hull speed boat?
A single hull boat has only one hull, which is the standard for boats. Catamarans have two, or twin hulls.
How fast does a schooner go?
This depends upon its water line length. The maximum top speed of a schooner is limited by its waterline and its effective sail area and sail plan. The maximum theoretical speed is calculated by taking its hull length at the water line (not overall length), find its square root, then multiplying that value by 1.3.
How do you find hull speed of a sailboat?
To determine the hull speed of a sailboat, multiply the square root of the length at the water line by 1.34. The answer will be in nautical miles per hour.
Maximum speed of a 747?
The maximum speed of a 747 is Mach 0.92.
What is the maximum speed of a MCA?
The maximum speed of MCA is 10 MHz
How does the shape of a boat's hull affect the speed?
How does hull shape affect the speed of a boat? When trying to get the most speed out of your boat, you may want to consider how the hull shape affects the speed of the boat. "Hydrodynamic" is a term that is used when determining the motion or flow of water. It is similar to the more familiar term "aerodynamic," which relates to the flow of air. The speed of a boat is correlated to its hydrodynamic efficiency, and the hydrodynamic efficiency is determined by the shape of the hull of the boat. The hull of the boat is the first area to be hit by water as you speed forward. A round or square hull will connect with the water like a force that is pushing against it. As the force of the water hits the boat hull straight on, the boat must push the water out of the way before it can attain optimal speed. This limitation of the boat's ability to get to a higher speed quickly is known as drag, and is affected by the hull shape. A boat hull shape that is pointed allows the water to flow around the boat quickly. The less water that the hull needs to move out of the way, the faster the boat will go. How hull shape affects the speed of a boat is one factor that the military had taken into consideration when they started to build the V-shape hull design. This shape offers the most hydrodynamic efficiency, which gives the military a boat that can cut across water with little drag and perform well at high speeds.
