Hull Speed

[Lance Jones]

I've lost the mathematical formula for figuring the THS of the 34. Does anyone know what the Theoretical Hull Speed is of the C-34?

[derekp]

try this link.
http://www.sailingusa.info/cal__hull_speed.htm

[Ken Heyman]

roughly --its 1.3 times the square root of the water line. So if a boat has a 25 foot water line the HS would be 6.5 (knots -I believe).
I'm certain you will find more precision on google or wikipedia,

Ken

[Lance Jones]

Thank you! The US Sailing site has it at 7.23 using their calculator. How many of you have exceeded this speed? I know I have (At least the GPS said so.)

[Stu Jackson]

I'd guess almost all of us have at one time or another.  Surfing down waves coming back into the Golden gate on breezy day we hit 10.9, but the knot meter isn't calibrated.  It's all relative.

[Lance Jones]

The only reason I asked is that I do find myself on great wind days able to consistently hit 7.1 - 7.5. Yesterday, I hit 8.1. What a great boat!

[WTunnessen]

8 knots seems pretty good if your not surfing as well or have a favorable tide. 

Do you have a folding prop?

[Tom Madden]

one thing to consider in assessing your speed using GPS (which measures speed over ground, not the speed thru the water) is the impact of the current you are in.  if the current is going the same direction as you ( for example, at 10 knots ) then your SOG will be much better than your speed thru the water (i.e. hull speed.)

[Jeff_McKinney]

I've clocked 9.2 SOG on a beam reach (with witnesses), 15 degrees of heel, balanced helm, clean bottom, folding prop.

What a rush! 

[Lance Jones]

All that about current is true. However, I'm on Lake Lanier in Georgia. Little, if any, current available. Well, that sucking noise is Florida and Alabama trying to suck our lake dry.....

[Bobg]

I have hit 8.6 on lake superior, 135 genoa and full main, about 20 degrees heel, you are right what a rush,

I was reading a book the other day, a guy was asked if he would like to go sailing, the person replied that if he wanted to sail, he would buy a rv and cross North Dakota keeping the speed below 7 miles an hour.  I thought it was funny.

[Bill Asbury]

Considering the windage a motor home would have in a North Dakota ground blizzard he might be hard-pressed to hold his speed under 10 knots...:-)
Bill

[Jeff_McKinney]

Would that RV speed be 10 knots on the long axis or getting blown sideways across the prairie?   

[Albreen]

Another reason for the increase above theoretical hull speed is the angle of heel  - the angle of heel contributes to boat lenght at the waterline. So, in essence you have more waterline and therefore more speed potential. But, I have no idea the coorelation of angle of heel to speed.....

[Roger Blake]

The more heel I have, the faster I seem to go.