?? O'DAY 23 Hull Speed?

[bella bu]

What is the hull speed of the o'day 23. and does that mean that is the fastest the boat will go?

 

[kpgraci]

LWL for an O'Day 23 is = 19'6", Using the Hull Speed formula of 1.34 * SQRT(LWL)

1.34 * 4.415 = 5.9 Kts

Hull speed is the point at which a displacement hull can easily move through the water. To go faster than that speed considerable additional power is required, so under sail, that is the expected maximum. Note that I have gotten my boat above this theoretical number, so while I'm sure the science is sound it should mainly be be used as a reference when comparing boats, but don't expect to exceed this number on a regular basis.

 

[RichBone]

The LWL of an O'day 23 is 19.39'
Here's two calculators and some background-

http://www.ehow.com/how_5970095_calculate-hull-speed.html
http://www.sailingusa.info/cal__hull_speed.htm
http://www.image-ination.com/sailcalc.html
http://www.boats.com/boat-content/2010/03/crunching-numbers-hull-speed-boat-length/
http://www.sailnet.com/forums/learning-sail-articles/18854-hull-speed-demystified.html
http://en.wikipedia.org/wiki/Hull_speed


Rich

 

[1977oday22]

On a good day under sail, I can usually hit 4.5-5.5 on my 22.
When motoring I usually hit about 4-5.

 

[kpgraci]

On a good day under sail, I can usually hit 4.5-5.5 on my 22.
When motoring I usually hit about 4-5.

We get the same range. I have a tracking program that automatically records position and speed and we hit 6.1 for a brief period on a beam reach with 15 kt winds. Before and after that we were solidly 5.5. I didn't know until I looked at the log. Hull speed for the 22 is 5.86, give or take.

I have read that the 1.34 in the formula could range from 1 to 1.5 depending on the specific hull profile, but 1.34 is normally cited.