Bosun Higgs
N/A
Yes it does!
Have another look. The hull shape is more 1970 / 1980 than 2010 Benny if you see what I mean. So being upright isnt as critical as it is with the wide stern flat bottomed boats but it still does help.
racing - windward speed help
- Thread starter Bosun Higgs
- Start date
Yes it does!
Have another look. The hull shape is more 1970 / 1980 than 2010 Benny if you see what I mean. So being upright isnt as critical as it is with the wide stern flat bottomed boats but it still does help.
Bosun Higgs
N/A
So what size of shift would you tack on since the wind is always going to be oscillating about a mean. I'm really not with this since if you are laying the mark or even within 20 degrees of it, the other tack will drastically reduce your VMG to the mark. And whilst the wind does move about, it doesnt do so by more than 20 degrees at most within the half hour of a leg.
Juniperskip
New member
Without confusing the whole debate, tidal stream may mean you ingnore shifts to keep in a tidal shadow or out of the stream. In the Solent tide is King in most areas.
On your trim issue, do you sail with much twist in the main? Another good way of reducing heel. One of my previous boats needed lots of twist one did not so experiment. Try looking at your pollars and writing down what the boat is predicted to do in certain wind strengths and then use as a trim target.
Bosun Higgs
N/A
We sail the bristol channel so we do have tides . What we dont have are polars and I cant find any for the boat anywhere. Might see if the designer has any.
I think I am going to have to do what someone earlier on has suggested - keep a notebook of performance and settings and then systematically experiment. There have been lots of good suggestions and a few which assume we are complete numpties but any help is appreciated.
We came second on corrected time at the weekend but that was PY handicap which adjusts slowly to performance. On IRC numbers ( we have an old CHS handicap) we were mid fleet and about 3% slower overall than the J109 winner. But then it was a J boat day - neap tides, racoing over high water, wind across tide at 20kn and flat water as a result. It will be a different story if we get some rough stuff.
Anyway at the risk of repeating myself, the concern was our speed to windward against the boats we would expect to match. Off wind was fine but up wind seemed poor.
. What we dont have are polars and I cant find any for the boat anywhere. Might see if the designer has any.I think I am going to have to do what someone earlier on has suggested - keep a notebook of performance and settings and then systematically experiment. There have been lots of good suggestions and a few which assume we are complete numpties
but any help is appreciated. We came second on corrected time at the weekend but that was PY handicap which adjusts slowly to performance. On IRC numbers ( we have an old CHS handicap) we were mid fleet and about 3% slower overall than the J109 winner. But then it was a J boat day - neap tides, racoing over high water, wind across tide at 20kn and flat water as a result. It will be a different story if we get some rough stuff.
Anyway at the risk of repeating myself, the concern was our speed to windward against the boats we would expect to match. Off wind was fine but up wind seemed poor.
Robin
Well-known member
It might reduce the instrument reading VMG to the mark in the case you mention but not the true one, because sooner or later you WILL have to tack to reach the mark. Tacking on the shifts means several small tacks instead of two longer ones, but the angle between the smaller ones will be much less. If you accept a 20 deg shift in part of a half hour leg you have just settled for back of the fleet! A 5 deg shift that shifts back and then goes 5 degs the other side of the mean is a difference of 10 degs on the tack angle, better than the pointing improvement you'd get from a new sail?
This really comes down to 'feel' or 'instinct' I guess because nobody knows how long a shift will last so you have to make a judgement call. Watching how other boats are doing a bit farther away (especially ahead) might give an idea? One thing is also for sure which is if you are in dirty wind from another boat, even if you are on the best tack for the current wind, is a definite NO, so tack away to find clear air then tack back. Look on the windward leg as a funnel that narrows to the target mark, as you get closer tack lengths get smaller but at any one time one side of that funnel may well pay off better than the other side or even the middle. It might pay to sail one longer tack over to nearer one edge then shorter tacks to the mark or it might not, judgement call! Same goes for wind strength, there might be more of it over one side than the other. Tide? Is there more of it (or less foul tide) over one side or the other? Seastate? Same again, one side might be more sheltered and less 'stopping' than the other?
All the above notwithstanding, don't go too much out on a limb if you main competitor hasn't, not so easy to judge with handicap races though. Sometimes it just pays to stay between him and the mark and hope you don't let the mob past whilst you do, judgement call again.
Good example at my club is a real hot shot in X boats (open keelboat not the offshore ones). He pretty well always gets to the windward mark first even if he makes a rare bad start and yet there are plenty of others with all the top gear for pure boatspeed. At the other end of the fleet are many others that never tack for clear air and always take the straightest route but just as on the roads shortest route isn't always the fastest! The difference between first and last (and these are one designs) is incredible.
GruffT
New member
Just what North U Tactics book was written for.
http://www.marinechandlery.com/products/1863/209/nautical-books/north-u-tactics.aspx (Retailer changed to protect the innocent)
And let's not even get into persistent vs oscillating shift. :-D
Bosun Higgs
N/A
Thats fascinating stuff Robin. I know what you mean in the last para - we have two Sigma 33 in the fleet and their performance is totally different. Indeed we can always tell which of the two owners is helming the First by how well it does.
dt4134
New member
Laying the mark means you're on the layline. Tactics Rule of Thumb No. 4,325b Don't get there until you have to. It means you can no longer play the windshifts.
A regular 5 degrees windshift if played well will give you a huge advantage over those boats that ignore them.
The first thing to do with windshifts is to measure them before the start. Go close hauled, find out the mean and what the oscillations are. If you notice a trend (progressive shift) and no one else does you should be on a winner, literally, but generally you just want to calibrate your brain so you know what to expect. In theory you should write them down on a plot but I've found doing that is a more effective means of bringing rain than cloud seeding, so I try to remember the means and oscillations.
Then during the race compare your close-hauled course to your measured data. That tells you what to expect next. So when expecting a header, look for it on the water, watch the telltales and compass course and go for the tack when it arrives.
Know in advance whether you want to take the shift or not (there's hundreds of tactical reasons that might say don't take it, but can't be bothered, or we can't tack well, or it's hardly worth it aren't on the list). Having decided to take the next shift go for it as soon as it arrives, thinking about it or discussing it just wastes time. You know it is going to shift back so you have to get the benefit whilst you can.
Always be alert to progressive shifts (they're like lottery wins but are much rarer than you hope). Also be alert to shifts caused by the land as you can loose out if you treat these like conventional shifts. That latter is something where local knowledge gives you an advantage so remember these shifts and use them next race or next series.
Don't go to the corners of the beat unless there is a clear tactical advantage to be gained (often tidal, but can be flatter water). If in doubt don't do it. A progressive shift would say go to the corner, but you have to be certain.
And as I said, don't get on to the layline too early. There's nothing worse than having to crack sheets when the rest of the fleet benefit from a lift.
By the way, Tactics Rule of Thumb no. 1 is to always have a plan. Stick to it and evaluate it unemotionally afterwards. That way next week's plan can be better.
mcframe
New member
Great thread guys, thanks - donno how much Mrs McF will appreciate it next time we take the children to Ryde (May Bank Holiday, but I might have done a couple of JOG inshores by then) ;->
Allan
Well-known member
Bosun, during the race in question, the winner of the fleet two race was reefing his main when going upwind. He shook the reef out on all other legs. Have you thought of getting your crew to practise reefing? As a cruising sailor I know that my boat responds much better to reefing the main and standing more upright than reefing the genoa. He also had a new crew member onboard for Sunday's race, maybe a race instructor?
Allan
Allan
flaming
Well-known member
You really have got to tack on shifts.
Often your electronics should be able to give you a true wind reading, and one number is easier to remember! Depending on your setup and calibration it might not be that accurate, but ought to be able to give you trends.
Often your electronics should be able to give you a true wind reading, and one number is easier to remember! Depending on your setup and calibration it might not be that accurate, but ought to be able to give you trends.
Twister_Ken
Well-known member
Only on the headers, not the lifters!
flaming
Well-known member
Knew I was doing something wrong...
Bosun Higgs
N/A
Been down to the boat today to measure how much movement on the wheel corresponds to how much rudder angle. Not difficult to do since the rudder stock rises into the cockpit between two locker lids. Anyway, one wheel spoke is 5deg on the rudder which means we had as much as 20 to 25 degrees on the rudder at worst and typically 5 to 15 degrees going upwind. Clearly the boat was a bit overpressed / unbalanced.
And if I remember rightly, to steer the boat without rudder you sheet in the main to go into the wind and loosen the main sheet in the genny to go off wind. Which suggests that we had too much main out.
dt4134
New member
You had lee helm!
Bosun Higgs
N/A
No - we're misunderstanding each other. But I've got enough to go on now so I'll leave it at that
Allan
Well-known member
Good luck next Sunday.
Allan
Allan
Slowtack
Well-known member
For boatspeed thru the wind ranges.............
Fractional rig - reduce headsail first, then reef main.
Masthead rig - reef main first, then reduce headsail area
Fractional rig - reduce headsail first, then reef main.
Masthead rig - reef main first, then reduce headsail area
underdog
Active member
"but performed less well than we needed to do hard on the wind."
Had the same problem myself through our winter series. Fast down wind but slow up wind.
Am awaiting delivery of new sails. i.e new no 1 no 2 & main. Hope this will cure the problem.
What percentage uplift in performance can I expect from new sails? The existing sails are at least 10 years old.
Fractional rig, Clean hull, experienced crew.
Had the same problem myself through our winter series. Fast down wind but slow up wind.
Am awaiting delivery of new sails. i.e new no 1 no 2 & main. Hope this will cure the problem.
What percentage uplift in performance can I expect from new sails? The existing sails are at least 10 years old.
Fractional rig, Clean hull, experienced crew.
dt4134
New member
A lot.
Some sailmakers also include a teaching session on the water if you've spent enough money. If you're getting that make sure all your crew turn up and you all focus on what he has to say. It could give you as big an uplift in performance as the new sails themselves.