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Downwind sailing in a 'slow asymmetric'

Printed From: Yachts and Yachting Online
Category: Dinghy classes
Forum Name: Technique
Forum Discription: 'How to' section for dinghy questions and answers
URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=12896
Printed Date: 12 Dec 19 at 7:55am
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Topic: Downwind sailing in a 'slow asymmetric'
Posted By: Wetabix
Subject: Downwind sailing in a 'slow asymmetric'
Date Posted: 30 Oct 17 at 1:02pm
Does anyone know of a good book or article on downwind sailing in a slow asymmetric? I am particularly interested in the tactical nuances when sailing in a mixed fleet which contains boats such as the Phantom and K1 which run almost DDW. I have to take the asymmetric line and thus sail much greater distances . No problem when planing but in sub planing conditions I find that most 14 to 15 foot boats go pretty much the same speed downwind which makes a nonsense of the 100 point handicap difference



Replies:
Posted By: Gordon 1430
Date Posted: 30 Oct 17 at 1:16pm
Does your name give a hint as to what you sail?
I would imagine the Weta would struggle for number of races to get a sensible PY.
I race a lot against 400 on a mixture of courses and they win more than I do. We are racing in tidal
conditions so the extra grunt of the 400may help against the tide.


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Gordon
Phantom 1430


Posted By: H2
Date Posted: 30 Oct 17 at 1:53pm
If you sail on a pond then my experience is to sell the assym and get a singlehander if you want to be competitive!


Posted By: Wetabix
Date Posted: 30 Oct 17 at 4:25pm
Actually I had a single hander (a Phantom) but when I gybed it kept turning over and as I passed the age of 70 my enthusiasm for breathing Scottish water faded, so I bought what I thought was a Phantom with trainer wheels (a Weta). It does not turn upside down when it gybes and it can on occasion beat a 400 and even occasionally a Phantom , but it is work on a windward/leeward and no faster than a Laser Radial downwind. The K1 is particularly hard to beat. Sure, in 15 knots you are up there with the big boys and if the course is a wide triangle you may even win occasionally.I  learned my dinghy racing at the age of 55 during the asymmetric revolution and it was only when I read Higher Performance Sailing that I realised that it was a con. Frank Bethwaite states categorically that nothing slower than a 29er will work. To compound the misery I don't even have a boom so DDW is not an option. The Dart 15 doesn't have a boom either, so how do they treat the off wind legs? What does surprise me is the 90 degree gybing angle used by the 470 which could go DDW if it wanted to but doesn't. So: to repeat my question, could anyone recommend a good book?


Posted By: pondlife1736
Date Posted: 30 Oct 17 at 7:52pm
Dart 15 doesn't  have a kite of course, so will more or less go DDW to the mark, especially if it's light wind. Yes it's slow and can be frustrating in a handicap fleet. With the jib up you would head up a little to keep it full, but my experience is that max downwind speed is a long way from VMG even in a good breeze. Not sure why the lack of boom would be a factor.


Posted By: JimC
Date Posted: 30 Oct 17 at 8:33pm
Thing is the principle is much the same in any boat. Sail the apparent wind angle that gets you the best VMG, sail in the best wind and sail the shifts so you do the shortest course. The difficult part is knowing what the best apparent angle is in each wind strength, and that's boat specific so a book is unlikely to help.

In an ideal world you'd have a complete set of instrumentation as they have on bigger boats where you could record wind speed and direction and speed through the water and construct a polar. For most of us that isn't an option. I'd be tempted to work out a way I could have a series of graduated apparent wind angles marked, and then use a mobile phone with GPS log to do a series of runs maintaining as far as possible a constant apparent wind angle (with reasonable number of gybes to get true wind) and see if I could inform my thinking that way.


Posted By: craiggo
Date Posted: 30 Oct 17 at 8:36pm
DDW on Dart15s and 18s is all about pushing the main out as far as it will go. We used to stand up, grab the clew and push it right out past the shroud, then helm and crew lying on the front beam. It's all about reducing drag in conditions where you aren't at max hull speed. Lift the sterns up until the length of boat left immersed matches the speed you are doing.

On a Weta you could try the same with the main, and goosewing the spinnaker, also try and keep the two floats out of the water, unless it's breezy in which case get the kite flying and sitting up to windward try and keep the pressure up, bear away in the gusts and try and keep the windward float out of the water at all times.

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OK 2129
RS200 411


Posted By: Sam.Spoons
Date Posted: 30 Oct 17 at 9:34pm
Apparent wind boats (i.e. cats, tri's and skiffs) are always at a disadvantage in the light stuff when they can't get the apparent wind working. But when they can (and on a suitable course) they should have a corresponding advantage against slow boats so it's swings and roundabouts. Racing handicap means you can pick a boat that excels in the prevailing conditions at your club or pick a boat you love sailing or, if you're lucky, pick one boat that does both (I sail two boats I love sailing and one that suits the club conditions..... though that one may not last).

I spent many years racing Raceboards (and DIV 1 before that) and if any craft demonstrates the difference between DDW and apparent wind the Raceboard 7.5 does. up to a certain point DDW is way faster (bear in mind unlimited pumping is allowed) then, as soon as you are planing then sailing the angles pays off in spades.


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Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish"


Posted By: Guests
Date Posted: 31 Oct 17 at 11:32am
The problem here is the weakness or problem isn't yours, it's the boats. As a result, there isn't much you can do in changing your strategy or tactics to alter that; no amount of self improvement will make that go away. 

What might be most useful is some class racing so you can see where your strengths and weaknesses really lay, and try and work on them. As long as you are generally getting faster around the course you should also generally do better on handicap (although you will still find your craft is comparatively weak on a dean run). 


Posted By: Guests
Date Posted: 31 Oct 17 at 11:56am
So whilst it may not overcome loosing out to DDW boat, in terms of strategy and technique in a slow asymmetric, I'd offer this advice (for what it's worth), it might all be bread and butter to you; 

Below planing conditions wind shifts will be more important than pressure (like upwind). Fit a compass to your boat and just like you would on a beat gybe on the shifts (except do it on lifts). To start off, gybe on every 5 degree lift, then reduce this as you get a feel for how long the shift will last and how much ground you lose through the manoeuvre.  It's better to gybe too often to start of with, as it's far easier to tell when a gybe hasn't worked, then when it might have. It's also good for your boat handling, and ultimately, the better the gybes, the more shifts you can take advantage of. 

Try an get a feel for what are favourable numbers on each gybe, just as you would on each tack upwind. Do this before the race and remember them from each downwind. Even write them down if needed. This will help you get in to sync with the shifts quicker.

Another trick is to note whether you are rounding the windward mark on a lift or header. If it's a lift, gybe set, if its a header, straight set. 

Take transit on two objects as soon as you've set your kite around the windward. Then next lap you can compare your first heading. 

As breeze increases pressure becomes more important. For boats with a distinct 'speed hump' around the planing speed then pressure becomes critical to almost all else. Any day that presents these conditions just forget your racing results and spend it playing around transitioning between modes. Having a feel for this is difficult. The best way I can think of describing it is when the pressure increases and you can feel the boat sticking against it's wake. At this point a small heat up in angle, ootch with the shoulders and flick of the sheet should be enough to promote planing. As the boat lifts keep sheeting in for the new apparent. Look back at your trail through the water to gauge how large a change in angle was required to get up and going. If really successful your trail should 'S' as you head up, start to plane, then bear away with the headed apparent to a course not much higher than the original. 

Once planning, speed increases are more linear with increased pressure. Speed increases also give your apparent wind a header to, so it's a double win. Shifts are still important, but less than pressure. It may be worth sailing a lift, if it takes you toward a band of pressure. Sometimes it's also worth sailing above your best VMG course to get over to band of pressure quicker than a pack of boats around you. 

Once up and planning you want to be constantly looking around a how the patches of pressure are tracking and trying to link up a pattern of gusts. 

Being subject to both pressure and shifts, downwind laylines are a very fickle place to be. In light airs if you gybe too early you will struggle to get low enough, but the penalty for this is only another gybe, which you can take at a time that suits. In light airs if you gybe too late, you have to sail high. It won't be the best VMG, but not a disaster. Once it gets windy the lay-lines are much tougher as you gybe too late; in the worst situation you will have to drop the kite and make big losses.  

As for technique on how to to set the boat up; i don't know what you're sailing and these thing are often hugely class specific. But for me these have helped: Pay attention to tack length and head drop. Sometimes in light wind it can be good to give a few inches of separation from pole and mast to allow the kite it's own wind. Having a set of light wind, light weight sheets is very useful too. If you have a downhaul line on the kite, make sure this is light weight too (stripped back to core for tail end) so it's not collapsing the kite. 

Usually a little windward heal balances the rudder and encourages the kite to roll around to windward too.  

Hopefully some of that helps. Smile


Posted By: Wetabix
Date Posted: 31 Oct 17 at 12:29pm
Well thanks for all your interest, guys, - although none of you has actually answered the question ('is there a book....?). Things that do spring to mind are that you can't roll tack or roll gybe a trimaran so manoeuvres are expensive - every leg is likely to be a one gybe affair - and you can't pump a boat with no boom. I have got compasses and GPSs and Vmg calculators and the best Vmg is usually about 150 degrees TWA which is what you'd expect for a slow asymmetric. I think it's a lost cause - I shall put it down to experience and go and borrow a Laser with a masthead float!


Posted By: Guests
Date Posted: 31 Oct 17 at 12:43pm
Ha, but my post is long enough that it could be a book!

Maybe post in the multi-hull section? In slow asymmetric dinghies a roll gybe is about the least costly manoeuvre imaginable so that greatly changes strategy from a tri. 

Nick Craig's helming to win is based upon considerable success in slow asymmetric, but dinghies. 

Andy Rice has a book on 'sailing asymetrics' but I've not read any of it, but the front cover mentions cats. 



Posted By: H2
Date Posted: 31 Oct 17 at 1:19pm
Originally posted by Wetabix

I shall put it down to experience and go and borrow a Laser with a masthead float!

Which to be fair is what I recommended you did....although based on your other posts I would recommend swapping the Weta for a H2 Smile


Posted By: Gordon 1430
Date Posted: 31 Oct 17 at 1:52pm
Try a certain Online available book from Clive (fab100 I think) who posts on here as a general improvement book.
Although I cant remember how specific it might be about your issue, as I was looking at it to improve my Phantom sailing.
If all else fails another wee dram.
Good luck


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Gordon
Phantom 1430


Posted By: Sam.Spoons
Date Posted: 31 Oct 17 at 2:04pm
Originally posted by Wetabix

Well thanks for all your interest, guys, - although none of you has actually answered the question ('is there a book....?). Things that do spring to mind are that you can't roll tack or roll gybe a trimaran so manoeuvres are expensive - every leg is likely to be a one gybe affair - and you can't pump a boat with no boom. I have got compasses and GPSs and Vmg calculators and the best Vmg is usually about 150 degrees TWA which is what you'd expect for a slow asymmetric. I think it's a lost cause - I shall put it down to experience and go and borrow a Laser with a masthead float!

A book or WHY will help you get the best out of the Weta but you'll still be sailing a boat optimised for stronger breezes. As you say you'll have to accept that light winds are not going to flatter the boat (and I suspect that applies to amy multihull). OTOH I sail a Spice, a sort of overweight (nearly)skiff with a huge asymmetric. I can't sail it particularly well in a blow (simple incompetence combined with the lack of a regular crew) but I did win a race on handicap last year sailing it singlehanded in a drifter.


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Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish"


Posted By: pondlife1736
Date Posted: 02 Nov 17 at 5:29pm
Off topic, but out of interest, how does your club handicap you singlehanding the Spice?


Posted By: Sam.Spoons
Date Posted: 02 Nov 17 at 6:10pm
I argued that I would not use the kite to compensate Wink and was scored off 930. We don't take our racing too seriously and, as I sailed the following days race solo for continuity (the trophy was for the two races) in F3-4 and, as a consequence, recorded a DNF, nobody complained. I finished over a minute ahead on corrected in around 40 mins so I'm not sure if a 30 point penalty would have made enough difference and can't remember the exact times anyway.......

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Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish"


Posted By: Wetabix
Date Posted: 02 Nov 17 at 6:12pm
We don't have a Spice at the moment but if we did it would get the published PY if there is one. If there isn't one my guess is that it would get 950 as a trial number. We use PY where published with an increment of 30 for very slow boats to take account of adverse tide. Our problem is that we have a couple of National 8 Ultras sailing on an unpublished 'class recommended' 920, a Weta which has a published figure of 960 that doesn't work very well on windward/leewards and a K1 which is a keelboat and not actually eligible but it is unbeatable in 10 knots or so on a WW/LW.  Our weekly turnout has declined in recent years and there is a big divide in the ability level which means you can just about allocate the cups at the 5 minute gun. Still - I was sailing my boat this am in a temperature of 6 degrees and 5 knots of wind and no one else is likely to appear much before April. It is a superb recreational boat which can be enjoyed on many levels but I don't think I shall bother with racing in a mixed fleet next year.


Posted By: pondlife1736
Date Posted: 02 Nov 17 at 6:41pm
Originally posted by Sam.Spoons

We don't race too seriously but I was scored to the standard 930. I did not use the kite (not that it would have made any difference except to slow me down) and I sailed the following days race solo for continuity (the trophy was for the two races) though it was F3-4 which put me at a major disadvantage. I recorded a DNF in that race so nobody complained. Wink

I had an ISO for a while, singlehanding, and was surprised that a boat regarded as 'draggy' in light winds actually went rather well with only 1 person aboard! It all got a bit too much in any wind though, at least for this catamaran sailor. 
If you sail a multi-hull (I expect the Weta is similar in this respect) you have to expect dismal light wind performance relative to the rest of the handicap fleet and maybe sail or do something else on those days. For me on the Dart, the threshold is about 7-8 knots minimum. On the other hand you can enjoy 20 knots plus and be reasonably confident you won't go swimming so it's swings and roundabouts......


Posted By: Sam.Spoons
Date Posted: 02 Nov 17 at 7:26pm
Same issue with the Spice. The last published PN was 930, the CA caretaker Stuart Bailey recommended a PN of 950 being more reasonable as there were never enough returns to get the original EN altered and I suspect Topper suggested 930 in an attempt to make it look faster than it was.

With only 75kg onboard it is pretty sprightly in the light stuff  but I do ok in the Blaze in similar (and did on Raceboards too). Two up definitely slows the Spice down a bit in those conditions. I think the biggest difference crew weight makes is in the marginal stuff where you'll plane earlier if you're light.


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Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish"


Posted By: Wetabix
Date Posted: 08 Nov 17 at 9:21am
I bought Nick Craig's book. He is quite clear that if you are not planing you should soak. Of course you can almost always plane if you point up high enough but I guess once you are more than about forty degrees above DDW you won't be gaining anything except in a boat with a huge spinnaker. I suppose this answers my question? Hurrah!



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