A while back there was a thread regarding speeds attained by the 260. Frankly I was skeptical about some of the claims. Today with winds from 20 to 30 knots I hit 6.9 knots on the GPS sailing a broad reach under main alone and the motor in the water. Upwind with the main and jib (motor out of the water this time) I hit 6.2 knots. Over the winter I installed a new Idasailor rudder and tuned rigging per instructions found on this forum. I have only good things to say about the new rudder and tuning. I know there was some concern regarding the Idasailor rudder in this forum (about it being 8 inches shorter than the factory rudder) but i had absolutley no problems. In fact I had the boat heeled over farther than it has ever been and she held course without any problems. If anybody had any doubts about the difference a properly tuned boat and a performance rudder could make, let me assure it's like sailing a new boat. Rich H260
- Status
Rudder
Rich glad to hear your happy with the rudder. I have a 98 240. I just ordered the Ida Sailor 260 rudder. I wanted the extra 5 inches. I sail and race in deep water and draft was not an issue for me. They explained the rudders were identical except the draft for the 240 and 260. I'm hoping to get in the water by the 16th. I've already missed 2 races. I was forced to look for a new rudder after a kid ran a car into my original rudder while it was in front of my house getting the last coat of wax before launching for the season. Looking forward to getting it. I went to the trailersailor fourum. Several people there have been using Ida Sailor rudders on different makes for last 2 years. Nothing but praise so far. Sean Coerse 1998 Hunter 240 "Right Coerse"
Rich glad to hear your happy with the rudder. I have a 98 240. I just ordered the Ida Sailor 260 rudder. I wanted the extra 5 inches. I sail and race in deep water and draft was not an issue for me. They explained the rudders were identical except the draft for the 240 and 260. I'm hoping to get in the water by the 16th. I've already missed 2 races. I was forced to look for a new rudder after a kid ran a car into my original rudder while it was in front of my house getting the last coat of wax before launching for the season. Looking forward to getting it. I went to the trailersailor fourum. Several people there have been using Ida Sailor rudders on different makes for last 2 years. Nothing but praise so far. Sean Coerse 1998 Hunter 240 "Right Coerse"
GPS Speed
Rich, GPS is wonderful but is is not real good for speed in the water. The speed you were measuring was speed over land. I sail on the Potomac, where currents and tides can give me as much a a 2 knot difference between my speed over land and speed in the water. Your maximum speed in the water is determined by the length of the hull at the water line, and cannot be exceeded without planing. For the H260, it's in th 5.5 to 6 knot range. The rest of your speed had to be due to tides or currents.
Rich, GPS is wonderful but is is not real good for speed in the water. The speed you were measuring was speed over land. I sail on the Potomac, where currents and tides can give me as much a a 2 knot difference between my speed over land and speed in the water. Your maximum speed in the water is determined by the length of the hull at the water line, and cannot be exceeded without planing. For the H260, it's in th 5.5 to 6 knot range. The rest of your speed had to be due to tides or currents.
Max Hull speed for a 260
Max hull speed is the square root of the length of the waterline times 1.34. Per the Hunter site, the LWL for a 260 is 23'3", so a max hull speed would be just under 6.5 knots you can also go here for more information: http://www.cncphotoalbum.com/technical/hullspeed/hullspeed.htm Regards, -Jim-
Max hull speed is the square root of the length of the waterline times 1.34. Per the Hunter site, the LWL for a 260 is 23'3", so a max hull speed would be just under 6.5 knots you can also go here for more information: http://www.cncphotoalbum.com/technical/hullspeed/hullspeed.htm Regards, -Jim-
Sorry but
I sail my 260 on a lake with no tides and I have recorded speeds above 7 knots a number of times via GPS. I have maintained speeds of 6.6 knots for several minutes.
I sail my 260 on a lake with no tides and I have recorded speeds above 7 knots a number of times via GPS. I have maintained speeds of 6.6 knots for several minutes.
Alrighty then Calvin 
Unless you were surfing on waves while on a run or a broad reach(which could increase hull speed above the "limit") or you were running with a strong current (on a lake?) then I guess you have a boat that is an exception to physics *5 Regards, -Jim-
Unless you were surfing on waves while on a run or a broad reach(which could increase hull speed above the "limit") or you were running with a strong current (on a lake?) then I guess you have a boat that is an exception to physics *5 Regards, -Jim-
Hull Speed
Hull speed can often be broken when sailing off the wind. I've recorded 8.9 sustained on my H240 in 18 knots on a broad reach on the bay. Tide and waves were a factor. My GPS has hit 10 but never sustained it.
Hull speed can often be broken when sailing off the wind. I've recorded 8.9 sustained on my H240 in 18 knots on a broad reach on the bay. Tide and waves were a factor. My GPS has hit 10 but never sustained it.
Good Description
Jim, That is the best description I have seen. Thanks. I was doing the math in my head, so I underestimated.
Jim, That is the best description I have seen. Thanks. I was doing the math in my head, so I underestimated.
Doubting Thomas
This subject has come up before on this and other sailing forums. Those who have never had the experience of exceeding hull speed always point to the formulas. I would probably do the same if I had not experienced an unusually fast broad reach on a lake with no current and no significant waves to surf. We peaked at 7.8 and maintained 7.4 knots (see related link). Others have done same. Was my speedo perfectly calibrated? No, but it was close and the difference between hull speed, 6.4, and what we experienced was obvious even without a meter. When it happens, you'll know. FWIW, my degree is in mechanical engineering and I've had my share of fluid dynamics courses, so I do understand the theoretical hull speed concept. But life has taught me that science doesn't have all the answers. Ron Mehringer h26 Hydro-Therapy
This subject has come up before on this and other sailing forums. Those who have never had the experience of exceeding hull speed always point to the formulas. I would probably do the same if I had not experienced an unusually fast broad reach on a lake with no current and no significant waves to surf. We peaked at 7.8 and maintained 7.4 knots (see related link). Others have done same. Was my speedo perfectly calibrated? No, but it was close and the difference between hull speed, 6.4, and what we experienced was obvious even without a meter. When it happens, you'll know. FWIW, my degree is in mechanical engineering and I've had my share of fluid dynamics courses, so I do understand the theoretical hull speed concept. But life has taught me that science doesn't have all the answers. Ron Mehringer h26 Hydro-Therapy
hull speed physics
sorry jim, but ron's right. the 1.34 rule is not a law of physics (or more properly, fluid dynamics), but an empirical guide that developed over the years. modern hull designs can often exceed their theoretical speed derived from that rule. ask glenn henderson-his hulls with the "reflex" manage the boundary layer on the hull and produce less drag-and a longer effective waterline length when compared to earlier hulls on which the 1.34 is based. In any case, the spec'd wl (static) is never the sailing waterline, because most boats have a longer effective waterline (hence faster) when heeled 10-20 degrees.
sorry jim, but ron's right. the 1.34 rule is not a law of physics (or more properly, fluid dynamics), but an empirical guide that developed over the years. modern hull designs can often exceed their theoretical speed derived from that rule. ask glenn henderson-his hulls with the "reflex" manage the boundary layer on the hull and produce less drag-and a longer effective waterline length when compared to earlier hulls on which the 1.34 is based. In any case, the spec'd wl (static) is never the sailing waterline, because most boats have a longer effective waterline (hence faster) when heeled 10-20 degrees.
I learn something new on here all the time
I appreciate the comments and feedback based upon everyone's observations and personal experiance and I willingly concede the point of "theoretical vs observed" speeds through the water. Still, I would love to experiance an H260 that sustains 8.9 knots *bzz Regards to all! -Jim-
I appreciate the comments and feedback based upon everyone's observations and personal experiance and I willingly concede the point of "theoretical vs observed" speeds through the water. Still, I would love to experiance an H260 that sustains 8.9 knots *bzz Regards to all! -Jim-
I have a friend who fancies
himself as a sailing expert. He had provided the same formula for calculation of maximum hull speed that Jim provided. I had also been provided this formula in a sailing class. I also recently recorded speeds (on broad reach with the jib furled and the main reefed in 25 to 30 mph winds)in our h260 above the calculated maximum hull speed. My sailing "expert" friend maintained that if a sailboat exceeds maximum hull speed that it could sink. I don't know if this is true, but it got me to wondering if the boat began to exceed maximum hull speed (at the ordinary WL)and began to sink a little, would it be able to exceed the maximum hull speed due to the increase in the length of the boat at the water line? Any thoughts?
himself as a sailing expert. He had provided the same formula for calculation of maximum hull speed that Jim provided. I had also been provided this formula in a sailing class. I also recently recorded speeds (on broad reach with the jib furled and the main reefed in 25 to 30 mph winds)in our h260 above the calculated maximum hull speed. My sailing "expert" friend maintained that if a sailboat exceeds maximum hull speed that it could sink. I don't know if this is true, but it got me to wondering if the boat began to exceed maximum hull speed (at the ordinary WL)and began to sink a little, would it be able to exceed the maximum hull speed due to the increase in the length of the boat at the water line? Any thoughts?
Hull Speed
The boat gains water line as it heals. I've recorded highest speeds when surfing (riding down the face of the wave). When racing smaller boats you work the sails to stay on the face of the waves as long as possible. As you accelerate down the face of the waves the apparent wind moves forward. If you boat is not balanced this can cause the helm to load up and be hard to handle.
The boat gains water line as it heals. I've recorded highest speeds when surfing (riding down the face of the wave). When racing smaller boats you work the sails to stay on the face of the waves as long as possible. As you accelerate down the face of the waves the apparent wind moves forward. If you boat is not balanced this can cause the helm to load up and be hard to handle.
What a load of frogs wallop!
Length of water line. Yeh that is true that the longer the faster. BUT! If you rely on hull length to increase when healing then be prepared to sacrifice speed for the inherent shape of a yacht like a 260 means that it "is" faster the flatter she sails. Next time you are near your yacht check it out. It is much easier to propel a flat surface thru the water than a curved surface.
Length of water line. Yeh that is true that the longer the faster. BUT! If you rely on hull length to increase when healing then be prepared to sacrifice speed for the inherent shape of a yacht like a 260 means that it "is" faster the flatter she sails. Next time you are near your yacht check it out. It is much easier to propel a flat surface thru the water than a curved surface.
Enjoy the ride!
Ya know, I don't know why boats sometimes exceed hull speed. I'll leave those heady concepts to those smarter than I. All I know is when it happens, it's a blast so just enjoy the ride. Have fun and sail safe, Ron Mehringer h26 Hydro-Therapy
Ya know, I don't know why boats sometimes exceed hull speed. I'll leave those heady concepts to those smarter than I. All I know is when it happens, it's a blast so just enjoy the ride. Have fun and sail safe, Ron Mehringer h26 Hydro-Therapy
It's just a
The "Rule of Thumb" hull speed equation, "1.34 times the square root of LWL, or length of waterline" is just a simplified mathematical model of a heavy displacement hull. The equation was derived by Sir Anthony Deane in 1670 to estimate the speed of a British "Man-O'-War". Most, if not all, modern recreational sailboats are light displacement fin keel, wing keel, swing keel or centerboard sailboat that should be classified as semi-displacement hull. This means that their hull design will always exceed the classic hull speed equation. Dave Gerr, a Navel Architect from New York City, came up with another "Rule of Thumb" equation to approximate a recreational sailboat's hull speed. He wrote the books, the "Nature of Boats" and the "Propeller Handbook" (the industry-standard reference on propellers). He uses the sailboat's displacement, as well as LWL in his simplified equations. His equations are: D/L=(weight/2240)/(0.01 * LWL)^3 S/L = 8.26/(D/L)^0.311 Modern Semi-Displacement Hull Speed = S/L * LWL^0.5 You can do the math, or just use Carl's Sail Calculator. At the bottom of the page, Carl does both the Classical hull speed and Gerr's hull speed when calculating the propeller size. For a Hunter 260 the Classical hull speed is 6.46 knots and Gerr's hull speed is 8 knots. If you surf down waves you will exceed Gerr's hull speed equation. It's just a mathematical model of a typical recreational sailboat. As with most mathematical models, its just an approximation and should be used as "Rule of Thumb" to get you in the "Ballpark" range for real world boat speed. If you have a full keel heavy displacement sailboat, then the Classical hull speed equation should be closer to your actual boat speed. Carl's Sail Calculator http://www.image-ination.com/sailcalc.html Fair Winds, Clyde
The "Rule of Thumb" hull speed equation, "1.34 times the square root of LWL, or length of waterline" is just a simplified mathematical model of a heavy displacement hull. The equation was derived by Sir Anthony Deane in 1670 to estimate the speed of a British "Man-O'-War". Most, if not all, modern recreational sailboats are light displacement fin keel, wing keel, swing keel or centerboard sailboat that should be classified as semi-displacement hull. This means that their hull design will always exceed the classic hull speed equation. Dave Gerr, a Navel Architect from New York City, came up with another "Rule of Thumb" equation to approximate a recreational sailboat's hull speed. He wrote the books, the "Nature of Boats" and the "Propeller Handbook" (the industry-standard reference on propellers). He uses the sailboat's displacement, as well as LWL in his simplified equations. His equations are: D/L=(weight/2240)/(0.01 * LWL)^3 S/L = 8.26/(D/L)^0.311 Modern Semi-Displacement Hull Speed = S/L * LWL^0.5 You can do the math, or just use Carl's Sail Calculator. At the bottom of the page, Carl does both the Classical hull speed and Gerr's hull speed when calculating the propeller size. For a Hunter 260 the Classical hull speed is 6.46 knots and Gerr's hull speed is 8 knots. If you surf down waves you will exceed Gerr's hull speed equation. It's just a mathematical model of a typical recreational sailboat. As with most mathematical models, its just an approximation and should be used as "Rule of Thumb" to get you in the "Ballpark" range for real world boat speed. If you have a full keel heavy displacement sailboat, then the Classical hull speed equation should be closer to your actual boat speed. Carl's Sail Calculator http://www.image-ination.com/sailcalc.html Fair Winds, Clyde
Excellent Clyde!
Thanks for providing the information and the link. Maybe this hotly debated topic can finally be put to bed. Ron Mehringer h26 Hdyro-Therapy
Thanks for providing the information and the link. Maybe this hotly debated topic can finally be put to bed. Ron Mehringer h26 Hdyro-Therapy
- Status