Adjusting sail trim and rig tension to point higher?

Nico

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It depends on sea state and wind strength. Number one is to increase forestay tension to prevent sagging off to leeward. This is achieved via the backstay for a masthead rig. In lighter winds you can then ease the genoa halyard tension to the point where slight wrinkles appear. This gives a "finer entry" and pointing at the expense of sheer grunt.

On the main you can increase sheet tension, adjusting the sail angle via the traveller.

In lumpy seas it is often better to forego pointing in favour of power. Try entering a waypoint a long way (like 100 miles - it doesn't matter if it is on land) directly upwind then check the VMG on the GPS. You may find that easing off a couple of degrees will increase your VMG in certain conditions. Some boats have VMG upwind on the electronics.
 

alec

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Quote :

In lumpy seas it is often better to forego pointing in favour of power. Try entering a waypoint a long way (like 100 miles - it doesn't matter if it is on land) directly upwind then check the VMG on the GPS. You may find that easing off a couple of degrees will increase your VMG in certain conditions. Some boats have VMG upwind on the electronics.
================================================================



What a brilliant idea !


Another great tip learned........
 

falcon5

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In Light winds, increase head sail sag, by reducing RIG tension, ease the back stay, dont try and point but go for speed and once the boat is upto speed start slowly pointing while sheeting in the sails and putting a little more backstay on to increase forestay tension, when you hit a wave or tack, then go for speed first before trying to point.

In stronger winds, having done what the previous post says, also make sure that the outhaul on the mainsail is on hard, the boat is balanced with maximuim crew weight on the rail, and the more backstay you have on (which flattens the sail, but puts the draft in it further aft, the more cunningham you need to pull the draft back forward, but still always go for boat speed first and pointing second.
 

William_H

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Well not as easy as that. I have a theory that you should use your water peed meter (log to check on boat speed. A hull has a speed (hull speed) where if you exceed that speed then it takes a lot more power to gain a little speed increase. That speed is not a clearly defined point but rather a range of speeds where the faster you go the more effort needed to miantain and increase that speed. (in a disproportionate manner)

Now power comes from pointing. If everything is set right then the closer you sail to the wind the less power you get to drive the boat. conversely the further off the wind the more power you get, ergo more speed. However the faster the boat goes the more sailing off the wind you need to do to maintain that spped.

In other words you can point really high and sacrifice a little power but if you are already going near the max speed that is easily acheived then you won't lose much by popinting higher. Or you won't gain much by pointing lower.
So set yourself a target water speed and steer the boat to that speed and if it is exceeded then you a pointing too low. If you get lower than that speed you are pointing too high.
This of course works only in winds that are gutsy enough to give you near top speed. ie 15 knots or more (perhaps 10 knots)
The advantage also is that if you are sailing just above the best heading for pointing ie on the verge or slightly beyond onset of luffing then you will have to be helming accurately on every minor wind shift. It will also set you upn correctly for rougher water.

Yes by all means use your GPS to calculate VMG you may be able to determine a good hull speed for your boat. Or better still sail with someonmne else who is racing with a boat that performs similarly to yours. My 21fter's ideal is about 5 knots boat speed or perhaps slightly less. It is a fairly easily driven light boat.

All of the above will help with better pointing although they are mostly for stronger wind situations. Light wind at least around here tends to be very variable in direction which requires great concentration.

So rules for good performance.

Must have clean hull I scrub mine in the water before every race.

Must have sails exactly right for the conditions ie jib not too big.
(get rid of that roller blind up front, select a real jib with correct sheeting points) Yes I know I am alone here.

Helmsman must concentrate very hard. This is best done from the lee side of the boat with jib fully in view. Get others to keep lookout etc. Concentrate and be greedy for pointing and lifts....

In variable winds be prepared to tack on very short notice to follow the wind shifts. Try to get a feel for the oscilations of the wind to anticipate a shift. This especially in sheltered waters near hills etc.

Just keep working at it. A few years of racing will get you hungry for pointing and performance. olewill
 

flaming

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I would also add that the obove posts do give a good idea of how to set each sail up, however the real key is setting the sails up to complement each other.

Often you see a cruising boat sailing to windward with the Jib very nicely set but nothing's being done to the main, with the effect that it's nowhere near the centreline and is blocking the slot.
To see if you have set the two sails to work in harmony or to fight each other is quite easy.
Stand on the leward quater and sight up the slot. It should be even all the way up. If it isn't you need to change something. So then decide which sail is the more "right" at that moment and change the other. If you decide that the Jib is about right, but the slot is very closed at the top (also indicated by the front 1/3 of the main backwinding at the top, but very difficult to spot with a fully batterned main) then you need more sheet tension. If the main is right but the jib wrong then it's the cars that need moving, and the sheet tension changed for the new setting. It's quite hard to describe the process by text means so the best bet is to go out and experiment in different wind strengths, always with the goal of that nice even slot!

A quick google found this pic which illustrates a nice even slot.
Yacht%20view.gif
 

falcon5

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AGHHHHH, please never sit to leeward unless you need the weight on that side of the boat (ie in ultra light winds), always sit to windward and make sure you can see waves coming onto the bow and can also see at least 2 sets of tale tales, and dependant on the boat shape, weight, sail configaration will determine if the tale tales should both be streaming or the inside tale tale just lifting occassionally.
oh lets all go for a sail and try the boat, what is she and where is she kept:)
 

flaming

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[ QUOTE ]
AGHHHHH, please never sit to leeward unless you need the weight on that side of the boat (ie in ultra light winds), always sit to windward and make sure you can see waves coming onto the bow and can also see at least 2 sets of tale tales, and dependant on the boat shape, weight, sail configaration will determine if the tale tales should both be streaming or the inside tale tale just lifting occassionally.
oh lets all go for a sail and try the boat, what is she and where is she kept:)

[/ QUOTE ]

Totaly agree with that, sit to windward where you can see the luff of the Jib.

Is there scope for a forum tuning service!? Cruisers taking racers out for a day for some sail trim tips? It'll never happen I'm sure! /forums/images/graemlins/shocked.gif
 

MikeBz

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Much more information needed to be able to give specific help - type of boat/rig/conditions etc. As someone else has mentioned excessive headsail sag can be a killer. If you're not overpowered then in general flattening the mainsail can make your pointing worse - with a bermudan rig if mainsail is the dominant area (and nothing else is massively out of kilter) then pointing ability is largely determined by the mainsail, if the leach is too open then you'll fall off, if you're underpowered then you'll be slow and make more leeway.

Going too slowly and thus making excessive leeway has the same effect as poor pointing - this can be caused by any number of things, can just be as simple as a dirty bottom!

Mike
 

William_H

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Well I expected to get some argument but not on helming from the leeward side..... Perhaps it is my boat and others are different but I find that concentration on the jib luff and tell tales is enhanced because it is right in your face. I have to sit forward and lean out on the windward side to see all the jib luff. It has a very big main and smaller jib(s). It also means that one person can see what is to leeward. (collision is a real danger where I sail) In helming from this point I often have to shift to windward in a gust to keep the boat upright. But will always shift back for that feel of precision helming.
I do feel that a lot of helmsmen will be happy with keeping the boat movinng well in aproximately the right direction for the tack and so find they are falling away from the opposition. Racing close to other boats brings out the skill in helming on the wind I think. ollewill
 

flaming

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[ QUOTE ]
Well I expected to get some argument but not on helming from the leeward side..... Perhaps it is my boat and others are different but I find that concentration on the jib luff and tell tales is enhanced because it is right in your face. I have to sit forward and lean out on the windward side to see all the jib luff. It has a very big main and smaller jib(s). It also means that one person can see what is to leeward. (collision is a real danger where I sail) In helming from this point I often have to shift to windward in a gust to keep the boat upright. But will always shift back for that feel of precision helming.
I do feel that a lot of helmsmen will be happy with keeping the boat movinng well in aproximately the right direction for the tack and so find they are falling away from the opposition. Racing close to other boats brings out the skill in helming on the wind I think. ollewill

[/ QUOTE ]

Well you're right on close racing bringing out the good helms!
But anyone who can helm from windward will stretch away from you due to weight on the rail.

I race in a very tight fleet and regulary score top 3 overall in regattas. Here's what I do.

I sit to windward, I can see 2 sets of tell tales from where I sit, but it wouldn't matter if I could only see one as the work of setting the car so the tell tales break evenly is done before the start by the trimmers.
I have 2 modes - power and squeeze. In power mode I aim for both tell tales streaming, in squeeze mode (just used temporarily for tactical purposes) I aim to have the inner tell tale at about 45 degrees. This requires total concentration, so I am NOT the person responsible for looking out for crossing boats. That's the TacNav's job, my world is 2 pieces of wool for pretty much the whole beat. I have a tactical input, but in an ideal world I wouldn't as it's noticeable how much ground we loose to windward when my concentration is anywhere except the tell tales.

I only come off the rail and helm standing to leward when ducking a starboard tacker or rounding a bear away mark.
 

falcon5

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Helming, sail trim, boat balance etc are all a science aren't they? if only it was that easy.
The reason I said 2 sets of tale tales is that in most boats i sail once powered up and sailing in clear air going for max VMG generally the higher tale tales do break earlier "just" than the lower ones, so while i steer on the correct set of tale tales I use the set above as a prewarning of being close to the edge, if they all break perfectly together i find that in a one design fleet you are a degree or 2 lower and cannot hold your lane, but perhaps it what suites me, and for other helms it would not.
But is this why we love sailing, as one size does not fit all and we are always learning?
 

flaming

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[ QUOTE ]

But is this why we love sailing, as one size does not fit all and we are always learning?

[/ QUOTE ]

Exactly! The day I go sailing and don't learn anything will be the day I quit.
 

castaway

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I'm quite suprised that with all this talk of boat speed versus pointing, no one has mentioned lee bow effect.

Especially in the waters you sail in, (and I).. I would sacrifice almost anything to get any opposing current acting on my lee bow.

All best Nick
 

MikeBz

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[ QUOTE ]
I'm quite suprised that with all this talk of boat speed versus pointing, no one has mentioned lee bow effect.

Especially in the waters you sail in, (and I).. I would sacrifice almost anything to get any opposing current acting on my lee bow.

All best Nick

[/ QUOTE ]

http://www.destinationonedesign.com/prep/index.aspx?chapter=ef1a1d70de9643908888312af7e7952c [stand back] /forums/images/graemlins/grin.gif

The article over-simplifies it, we all know that there are practical situations where the lee-bow effect does have value.

Mike
 

flaming

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Lee bow effect is a myth. Think in terms of ground wind, sailing wind and apparent wind and it will become clear that there is no such thing.
 

MikeBz

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I understand why it's a myth in theory, however in practice the benefit of 'lee-bowing' can be tangible and significant. Here's one situation:

Light wind. Mark is dead uptide, wind is at 45deg. to tide (e.g. tide is from the N, wind is NE). On starboard tack I can choose to sail higher & slower and make the mark, with my bow slightly above the tide (the mythical lee-bow) or sail lower and faster and have to tack to make the mark. The thing that the 'myth' argument doesn't take into account is the effect the tide has on my apparent wind. On starboard tack, if I'm 'lee-bowing' then I get more apparent wind from a lifted (freer) direction. On port tack I'm sailing across the tide at 90 deg. so my apparent wind is weakened and headed significantly (the lighter the wind and the stronger the tide the more significant this is). This effect can be hugely significant. The boat which chooses to 'lee-bow' comes out a long way ahead of the one which sails lower & faster on starboard tack and then has to make the painfullly slow cross-tide tack on port.

Mike
 

PatrickB02

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There’s a useful series of articles on sail trim on the Dolphin Sails website, http://www.dolphinsails.com/spec.htm, under the heading “Sail Trim Care”. I wouldn't be surprised if other sailmakers' websites have similar. Also loads of books, ranging from basic to rocket science.

But if you really want to improve pointing, get a set of Dolphin’s pentex race sails – I inherited a set with my boat and they are fantastic!

No connection, just a very satisfied user.
 
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