Does anyone know what the hull speed of the h240 is? For those of you who have GPS or knot meters, what was your best speed. Finally, does anyone know what the race handicap rating for the h240 is? Thanks!
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Todd Mitchell
Online Hull Speed Calculators
The hull speed of your boat is approximately 6.3 knots. For fun you may want to go to the following pages that help you figure this out: http://www.anyboat.com/hull.htm http://www.fmyers.com/HullSpeed.html The formula for calculating the hull speed of a displacement hull vessel is: hull speed = squareroot(length of the water line) * 1.35 This multiplier, 1.35, is a typical speed/length ratio. The second link above lets you play with different speed/length ratios if your boat has something significantly different than the norm. I am not familiar with race handicaps ratings, sorry. I'm a family cruisin' kinda guy.
The hull speed of your boat is approximately 6.3 knots. For fun you may want to go to the following pages that help you figure this out: http://www.anyboat.com/hull.htm http://www.fmyers.com/HullSpeed.html The formula for calculating the hull speed of a displacement hull vessel is: hull speed = squareroot(length of the water line) * 1.35 This multiplier, 1.35, is a typical speed/length ratio. The second link above lets you play with different speed/length ratios if your boat has something significantly different than the norm. I am not familiar with race handicaps ratings, sorry. I'm a family cruisin' kinda guy.
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Been there
Hull speed is 1.34 * sqrt(DWL)
Hull speed is DEFINED as the speed of a gravity wave in water whose length equals the waterline of your boat. It is a function of your boat's waterline. Period. The constant 1.34 is calculated from the properties of water (density, viscosity, etc.) and the acceleration of gravity at earth's surface (32 feet per second squared). Hull speed is NOT a maximum speed for a displacement boat. The myth that hull speed is a maximum fools a lot of people. Calculting the maximum speed for a particular boat is quite complicated. You can find velocity prediction programs (VPPs), and what you'll quickly learn is that the better ones want more information about hull shape, CG, and dozens of other parameters than you have at hand.
Hull speed is DEFINED as the speed of a gravity wave in water whose length equals the waterline of your boat. It is a function of your boat's waterline. Period. The constant 1.34 is calculated from the properties of water (density, viscosity, etc.) and the acceleration of gravity at earth's surface (32 feet per second squared). Hull speed is NOT a maximum speed for a displacement boat. The myth that hull speed is a maximum fools a lot of people. Calculting the maximum speed for a particular boat is quite complicated. You can find velocity prediction programs (VPPs), and what you'll quickly learn is that the better ones want more information about hull shape, CG, and dozens of other parameters than you have at hand.
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Sean Coerse
Top speed
I have hit 9.4 knots on my GPS while sailing into littlecreek on a broad reach in 18 knots of wind with an incoming tide.
I have hit 9.4 knots on my GPS while sailing into littlecreek on a broad reach in 18 knots of wind with an incoming tide.
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Big T
Thanks guys! Also had similar experience.
Thanks for your inputs. I'll ditto the comment on the broad reach. I had a similar experience lately in Tampa bay when 12 knot winds which suddenly honked up to 20-25 knots. Thought I was going to go airborne. With shallows approaching, I decided to round up and roller furl the jib in.
Thanks for your inputs. I'll ditto the comment on the broad reach. I had a similar experience lately in Tampa bay when 12 knot winds which suddenly honked up to 20-25 knots. Thought I was going to go airborne. With shallows approaching, I decided to round up and roller furl the jib in.
Two observations re speed
I agree with "Been there"s comments; most Hunters will go faster than their theoretical hull speed because of the underwater hull shape (which the theoretical equation does not consider). My H23 will do over 6.5 kts of true boatspeed even though the theoretical hull speed is a little over 5 kts. The light displacement and flat hull bottom aft of the keel are part of the reason why. The best example that I can think of is Greg S. in Texas who can plane his H23 "Faster" at over 10 kts. Second point: GPS reads speed over ground (SOG) which is the same as the speed of the boat through the water only if there is no current. If you sail in an area with current or tidal stream, your GPS will not give you true boatspeed. A following current will increase SOG even though the boatspeed has not changed. The opposite is true for an opposing current. Still, GPS is hard to beat. A decent GPS costs less than even a basic knotmeter, it is a lot easier to install and besides it will give you all the position information you could possibly want. Peter S/V Raven
I agree with "Been there"s comments; most Hunters will go faster than their theoretical hull speed because of the underwater hull shape (which the theoretical equation does not consider). My H23 will do over 6.5 kts of true boatspeed even though the theoretical hull speed is a little over 5 kts. The light displacement and flat hull bottom aft of the keel are part of the reason why. The best example that I can think of is Greg S. in Texas who can plane his H23 "Faster" at over 10 kts. Second point: GPS reads speed over ground (SOG) which is the same as the speed of the boat through the water only if there is no current. If you sail in an area with current or tidal stream, your GPS will not give you true boatspeed. A following current will increase SOG even though the boatspeed has not changed. The opposite is true for an opposing current. Still, GPS is hard to beat. A decent GPS costs less than even a basic knotmeter, it is a lot easier to install and besides it will give you all the position information you could possibly want. Peter S/V Raven
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Been there
Hull speed of H23 is hair under 6 knots
With a 19'7" waterline, the boat's hull speed is 5.93 knots. Which given accuracy of common measurement, might as well be 6. Many sailboats will exceed hull speed in their favored conditions. Multihulls regularly exceed it by a lot.
With a 19'7" waterline, the boat's hull speed is 5.93 knots. Which given accuracy of common measurement, might as well be 6. Many sailboats will exceed hull speed in their favored conditions. Multihulls regularly exceed it by a lot.
Dohh!!
Ooops, I was multiplying LWL by 1.34 and THEN taking the square root. Anyway, my doughnut break is over and I need to get back to work here at the Springfield nuclear power plant. Peter S/V Raven
Ooops, I was multiplying LWL by 1.34 and THEN taking the square root. Anyway, my doughnut break is over and I need to get back to work here at the Springfield nuclear power plant. Peter S/V Raven
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ed Knebe
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