it wants to round up hard in a strong wind...why?

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Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
im looking for advice on how to trim it or tune it better....

this weekend I got the chance to sail in some of the strongest winds that ive been in..... and there were some surprises.
I was running the genoa which may have been too much by some peoples standards..
the water was white capping fairly good and had about two foot of chop with some powerboat wakes added in.....

I wanted to see what the boat would do... and aside from going really fast, it is hard to hold on a straight course in extreme wind........
the wind was strong and constant but it was also uneven..... it had its moments severity.... I had the boat all battened down and I tried to get it into a controlled knock down..... just for the experience.
but just about the time the bottom edge of the jib was about 6in from the water, and i had the tiller hard over trying to hold it off, but when it was ready, the rudder position made no difference to it..... it would all of a sudden turn itself into the wind..... then the sails would luff a bit until it caught the wind again and then it was back to sailing heeled over.... until the jib was near the water again, which was only about 30 seconds, then it was rounding up again..... i let out the jib a bit and the main as well and it made it a little more controllable, but I never could get to the knock down, as close as i got was getting the cabin window wet but I think that was only a wave.....
so im not sure what it would take for a knock done with this boat, but it seems pretty safe from that in its present configuration because just about the time the rail is steady in the water it rounds up.

my question is.... aside from avoiding practicing the knockdown maneuvers, LOL, what can I do to better tune the rig or trim the sails in strong winds? why does it round up so hard in strong winds? is this kind of normal behavior for a sailboat in these wind conditions? I think i should add a couple of inches to the front edge of my lower rudder board for more area and a better balance.... it was very hard to hold in the strong wind.
and im NOT asking if this is normal sailing, lol.... i know it's not, and im sure it looked stupid to anyone watching me, but i was in school learning about my boat in heavy wind...... I will never be one of the people who stay on the dock because the wind is too strong....

and of all the experienced I gained from this adventure, the single most important thing I learned was something that seemed like nothing when i rigged the boat..... I will pass it on here for anyone who wants a bit of advice from someone with first hand experience in the matter....
DONT EVER FORGET TO TIE A KNOT IN THE END OF YOUR MAIN SHEET.....
why?... well, you would of had to of been there for the full effect, but when the wind is blowing hard and you dont get the sheet cleated good after trimming..... its almost a panic situation when the boom slams into the shrouds and the tail end of your mainsheet has unreeved itself from the blocks and is dragging in the water from the end of the boom..... the wind and the waves dont stop...... and as the action is just beginning to pick up, you somehow have to figure out how to get it all back together quickly, providing everything is still standing and something didnt break.... I was lucky!
....I went looking for experience, and I got some. I wont ever forget the knot again.:doh:
 
Feb 26, 2004
22,986
Catalina 34 224 Maple Bay, BC, Canada
Good for you!

The answer is you have a well designed boat that does what it is supposed to do: keep you safe.

When boats round up in heavy winds, it means you have too much sail up. But you knew that already, dinchya? :)
 

Kermit

.
Jul 31, 2010
5,669
AquaCat 12.5 17342 Wateree Lake, SC
Could be your rudder came out of the water. With no rudder the boat will round up. That's how my H23 works. Or is supposed to.
 
Oct 26, 2005
2,057
- - Satellite Beach, FL.
The angle of the rudder caused it to lose purchase and the boat headed up like it's supposed to. This is a good thing. It can keep people from getting hurt or killed.
Go rent a small catamaran and sail it in those conditions. You'll get knocked down all you want. I promise.
 

DougM

.
Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
That is a symptom of weather helm. As the boat heels over and starts to round up, its probable that a good portion of the rudder is out of the water. Hence no response to the helm. Drop the traveller to help the boat sail more upright. A smaller headsail in windy conditions would help, or roller furl the genny (which doesn't help sail shape). Next step reef the main. Also if sailing close to the wind, sails should be as flat as possible (outhaul, downhaul, vang). If your sails are baggy to start with, the situation will be exacerbated. A lot depends upon the individual boat, changing mast rake angle so that it is more vertical helps to change the center of effort and can help to alleviate some of the weather helm.
 
Jan 14, 2010
18
ODAY 22 LAKE ONTARIO, NY
im looking for advice on how to trim it or tune it better....

this weekend I got the chance to sail in some of the strongest winds that ive been in..... and there were some surprises.
I was running the genoa which may have been too much by some peoples standards..
the water was white capping fairly good and had about two foot of chop with some powerboat wakes added in.....

I wanted to see what the boat would do... and aside from going really fast, it is hard to hold on a straight course in extreme wind........
the wind was strong and constant but it was also uneven..... it had its moments severity.... I had the boat all battened down and I tried to get it into a controlled knock down..... just for the experience.
but just about the time the bottom edge of the jib was about 6in from the water, and i had the tiller hard over trying to hold it off, but when it was ready, the rudder position made no difference to it..... it would all of a sudden turn itself into the wind..... then the sails would luff a bit until it caught the wind again and then it was back to sailing heeled over.... until the jib was near the water again, which was only about 30 seconds, then it was rounding up again..... i let out the jib a bit and the main as well and it made it a little more controllable, but I never could get to the knock down, as close as i got was getting the cabin window wet but I think that was only a wave.....
so im not sure what it would take for a knock done with this boat, but it seems pretty safe from that in its present configuration because just about the time the rail is steady in the water it rounds up.

my question is.... aside from avoiding practicing the knockdown maneuvers, LOL, what can I do to better tune the rig or trim the sails in strong winds? why does it round up so hard in strong winds? is this kind of normal behavior for a sailboat in these wind conditions? I think i should add a couple of inches to the front edge of my lower rudder board for more area and a better balance.... it was very hard to hold in the strong wind.
and im NOT asking if this is normal sailing, lol.... i know it's not, and im sure it looked stupid to anyone watching me, but i was in school learning about my boat in heavy wind...... I will never be one of the people who stay on the dock because the wind is too strong....

and of all the experienced I gained from this adventure, the single most important thing I learned was something that seemed like nothing when i rigged the boat..... I will pass it on here for anyone who wants a bit of advice from someone with first hand experience in the matter....
DONT EVER FORGET TO TIE A KNOT IN THE END OF YOUR MAIN SHEET.....
why?... well, you would of had to of been there for the full effect, but when the wind is blowing hard and you dont get the sheet cleated good after trimming..... its almost a panic situation when the boom slams into the shrouds and the tail end of your mainsheet has unreeved itself from the blocks and is dragging in the water from the end of the boom..... the wind and the waves dont stop...... and as the action is just beginning to pick up, you somehow have to figure out how to get it all back together quickly, providing everything is still standing and something didnt break.... I was lucky!
....I went looking for experience, and I got some. I wont ever forget the knot again.:doh:
I have an O'day 22 and it does the same thing, depending on wind strength I reef the main or just spill a llittle wind from the main. This is a normal condition.
 

RichH

.
Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
There's a combination of elements that cause 'rounding up' during heavy winds:
* elasticity of the rigging wire
* elasticity of the sail material
* shape of the hull sides

You dont mention that you were reefed ......

• If the rigging isnt 'set up' with the proper TENSION, especially the forestay, the rig will stretch and the headsail will be operating 'off to the leeward side' of the boat ... this causes the boat to 'skid' sideways (towards leewards) and the resultant stretch in the forestay will cause the position of max. draft in the headsail to become 'draft aft', the sail will 'powewr up' with increased amount of draft, .... and with a corresponding leech shape that is 'hooked up' towards weather. The performance result is 'heavy helm pressure' (but isnt weather helm), extreme heeling, 'cranky boat', etc.
In such conditions the BACKSTAY (which reacts to the forestay) should have its tension increased. Here's how to do this as you want the 'sag' in the forestay to MATCH the what was cut into the luff of the jib/genoa. If this relationship of forestay tension TO cut of the jib isnt 'matched' .... skiding boat, heavy helm (not weather helm), aggressive heeling, etc."
http://www.ftp.tognews.com/GoogleFiles/Matching Luff Hollow.pdf

• Ditto mainsail material (especially dacron) is elastic and if sailed (full up) in heavy winds .... the stretch will cause increased draft and draft-aft with a 'hooked up to weather' shape --- WEATHER HELM!!! The primary 'control' vs. a stretching mainsail is OUTHAUL tension (amount of draft) and HALYARD tension (the fore-aft position of MAX. draft).
If you want to sail with full up sails in 'heavy' winds, consider to have a "cunningham" added to the mainsail .... helps with the 'flattening' and correct fore/aft position of max. draft in the mainsail.
Here's how to set up / raise (any wind strength) - for 'heavy winds' you will want the draft position to be forward ..... and leech to be 'tripped' or 'open' - so that the shape of the leech is FLAT shaped (or 'slightly' pointing towards leeward):
http://forums.sbo.sailboatowners.com/showthread.php?t=120970 post #1

When in "heavy" winds if you dont compensate for stretching sails and rigging ... the action of the wind will increase the amount of draft and move the position of max. draft 'more aft'

• When most conventional shaped boats lay over of their sides, the 'roundness' of the side tends to 'turn' the boat into the wind .... you must compensate with FLATTER sails and 'Tighter' rigging.

In 'heavy winds', you really have to adjust rig tension and halyard/outhaul etc. tension (best done ... on the 'fly').

99% of apparent so-called 'weather helm' on a sailboat is due to improperly raised / stretched out ('shaped') sails and 'poorly adjusted' rigging. !!!!!!!!!!!!!!!

hope this helps. :)
 
Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
thank you for the responses....
the rudder is in the water far enough. im a fairly big guy and its all i want to hold on to it..... and its hard over.
and as for too much sail.... yes i knew that, LOL.... but i wanted to see how it reacts.

and i do have a 100% head sail.... the genoa i was running is about 150....

which sail has more effect on causing it to round up?..... or does it have more to do with the shape of the hull when its heeled?..

I have removed some of the rake from the mast, but I didnt check it using the halyard as a plumb bob while it was in the water..... so i have no idea of what i have in it.
 
Nov 2, 2010
114
Precision 28 Ashland, Oregon
In general, most keelboats are designed so that the rudder is shallower than the keel and therefore it will come out of the water first. Once that happens the boat will round up. Also I agree that old stretched out sails can never be flat enough for heavier air. Also agree about rig tuning. BTW, this severe rounding up that happens on keelboats is sometime also known as 'self-righting' (or part of 'self-righting') and is entirely by design...
 

RichH

.
Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
FWIW .... a 'perfectly set up' boat (most boats) even with full sails up in 'heavy wind' will have little to NO 'weather helm'. ;-)
 

RichH

.
Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
In general, most keelboats are designed so that the rudder is shallower than the keel and therefore it will come out of the water first. Once that happens the boat will round up. Also I agree that old stretched out sails can never be flat enough for heavier air. Also agree about rig tuning. BTW, this severe rounding up that happens on keelboats is sometime also known as 'self-righting' (or part of 'self-righting') and is entirely by design...
What you are describing is a 'fault' of boats with *non totally submerged* rudders ... the rudder begins to cavitate, the cavitation produces 'suction' and the atmospheric air is drawn down along the faces of the rudder .... and the rudder becomes almost totally 'useless'.

Most keel boats have submerged rudders, with little to no apparent 'connection' to the 'air'. Boats that have 'pintel hung' rudders from the stern can easily 'cavitate' and 'suck air'.

Many of the newer fat-assed boats have twin rudders so that when the boat is well heeled over at least one of the rudders is always submerged .... a 1890s design derived from ILYA scows.
 
Nov 2, 2010
114
Precision 28 Ashland, Oregon
Rich, yes I agree with both of those statements. Question: what percentage of boats are 'perfectly set up'?? Just curious what you would estimate...
 
May 11, 2007
14
C&C 35 MkII Port Jefferson, NY
Too much sail behind the mast

When your boat veers strongly into the wind with strong gusts it is a sure sign you have too much sail aft of your "center of lateral resistance"--generally the mast. You say you had a full Genoa, about 50% of which is aft the mast, as well as full main. Your center of effort was well behind the mast which will turn you into the wind. This link has an excellent explanation.

http://www.sailingusa.info/sailboat_balance.htm
 
May 11, 2005
3,431
Seidelman S37 Slidell, La.
Every boat is different

I have found that no matter what, every boat has a point where it wants to round up. Some you can control with some effort, some not. I had a 28' S2, that you basically couldn't sail with more than 20 degrees of heel. It basically was going to round up. On the other side of that coin, years ago I had a Chrysler 22, and it loved to be sailed with the rail in the water. While all of the above statements are correct, the basic design of the boat is going to be a big determining factor.
 

RichH

.
Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
Rich, yes I agree with both of those statements. Question: what percentage of boats are 'perfectly set up'?? Just curious what you would estimate...
My guesstimate is: probably very few are 'set up' correctly and with properly *shaped* (I dont mean trimmed) sails.
Not even 'all' racers have a perfectly set up boat ... or they'd all be crossing the finish line at the exact same time when racing 'one design' classes.

For the 'cruising' sailor, coming close to good shape, good trim, good rig tension/adjustment, 'light helm pressure' in almost all wind/wave conditions, etc. ... is simply a 'safety issue'. ;-)
 

RichH

.
Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
When your boat veers strongly into the wind with strong gusts it is a sure sign you have too much sail aft of your "center of lateral resistance"--generally the mast. You say you had a full Genoa, about 50% of which is aft the mast, as well as full main. Your center of effort was well behind the mast which will turn you into the wind. This link has an excellent explanation.

http://www.sailingusa.info/sailboat_balance.htm
Id disagree with a LOT of that as the CLR to CE ratio only sets a boat to be able to be heave-to or not. Actually most boats are designed with latent 'lee helm' if you carefully calculate the CLR-CE ratios as 'moment forces' vs 'projected areas'.
So too most boats with mast head rigs can easily sail quite well with JIB/GENOA ONLY and without any 'weather helm' .... its all in the 'dynamics' (hydro and aero).
The aerodynamic flow over sails is a dynamic function and can be varied simply by sail shape, etc. Its only when a boat is so far over onto her beam ends at maximum heel and the keel/centerboard 'loses its effectiveness' and the boat is now skidding off to leeward does the balance become 'uncontrolled'. As regards to sail area 'projections', the suction peak (maximum 'thrust') of aerodynamic flow occurs 'just behind' the luff ... dynamics.


;-)
 

Nodak7

.
Sep 28, 2008
1,256
Hunter 41DS Punta Gorda, FL
Good for you!

The answer is you have a well designed boat that does what it is supposed to do: keep you safe.

When boats round up in heavy winds, it means you have too much sail up. But you knew that already, dinchya? :)
Centerline what Stu says here is absolutely correct. The boat is designed to round up when you are overpowered. You need to either reduce sail, let out some sheet or let the traveler out! Or all the above. It will reduce your heel and give you better control with the rudder!

I had the same concerns when first out in big blows. Good luck!
 

JohnS

.
Sep 25, 2008
177
Islander (Wayfarer/McGlasson) 32 St Georges Harbor
I always thought it depended on the hull, and that for most cruising boats, as the boat heels, the center of lateral resistance moves forward. To have a balanced helm at both 15 degrees heel and 45 degree heel seems unlikely, no?
 
Feb 26, 2009
716
Oday 30 Anchor Yacht Club, Bristol PA
All because you won't, can't, don't know how to reef and reduce sail; (Assuming a Mac21 has reef points) as a center boarder, you could have broached and been in trouble, could have lost the mast, could have broken the tiller and or rudder. A gybe slapping the mast over hard could have ripped the mainsheet out of the boat too.. or worse.. now that you know what not to do... (consider yourself scolded LOL)

Your boat at least had the good "sense" to round up! she was basically yelling reduce sail! glad you had fun and came back safe. :)
 
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