Pointing to Problems with Pointing

I'm sure I'be blogged on this before, so this is a kind of reblogg spawned by some discussions of late of what hinders some boats in their performance.

so what do people mainly complain about?

Some people complain or observe from outside, that a given boat just does not sail as high on the wind when close hauled as her rivals in OD or 'near peers' in handicap fleetas.

Alternatively people get frustrated with pointing in  individual races, often during weather and a sea state they are not used to. Or it seems the boat points well only in light or only in heavy airs.

All of these issues can be examined and overcome by considering the following blocks as where the problem lies, amd that it may take knowledge and actions in all thjree to match your peers on the race course or exceed them.

1) Rig and Sails

2) Running Rigging and Sail Trim

3) Skill set and Style of Sailing that boat

1 a. Rig Tune- Small changes matter.

A lot of mid fleet sailors really don't bother to alter their rig tension throughout an entire season. There are a very few boats which you can get away with this, and any regatta machine will benefit greatly from judicous use of spanners and screwdriver shafts on the bottle screws.

Why bother adjusting the rig, it is in a nice stable setting from which we can trim the sails for all conditions ? I used to think this, and in fact given uncertain conditions ahead,  you can set the rig on an average set of tensions, mast bend and triangle dimensions fore and aft. Or you can set a very stiff set up for heavier weather you start in, and then ease sail settings out to compensate if the wind dies.

Howevver think of this to get you out of this comfort zone : how much difference does two inches of trimming make to the jib or mainsheet? It can make all the difference of course between a mediocre trimmed sail and an optimally trimmed sail.

In terms of pointing, this is very prominent if there is a degree of adjustability as with most racing designs. Without a backstay on a fractional rig,  the lenght of just the forestay can alter the rake markeably, and move the whole centre of effort on the  sail forward and back. Just a few inches makes a big difference because of the shorter chord length at the top there relative to that small change, and how the COE then alters around the balance point with the keel and the foresail. 

Think of the advantage of getting that just right foe your boat for the conditions that day ! It is like dialling in an extra bit of magic, in the same way a slight in or out on the sheets makes the boat go sweeter.

Lenghtening the forestay will add more rake and to a point where you loose this benefit because the leech of the mainsail can no longer be trimmed taught enough for beating, or the backstay will no longer tighten any more and thus the forestay just becomes slack, and sags off to lee rather than jut allowing the mast to have more rake.

On a fractional rig, slipping out an inch of forestay may result in several times that distance that the mast top moves backwards, pivoting on its base. I would say that on a typical sports boat you are looking to add or subtract 3-4 inches each way from a mid wind mid point. On a fifty footer it could be several feet each way.

On a Masthead rig, the length of the forestay and the dimensions of the fore triangle can actually be very wrong. I sailed on a MH Figaro II which had terrible poining issues - the boat just stalled on both sails. What was needed was a longer setting on the forestay and that the mast foot, rake and prebend be adjusted, but only very slightly with the foot going forward about an inch. The end effect was the correct rake and tension on the genoa luff. The mast top probably moved back less than a foot from its original bad position, while the lower and mid mast were a little forward, just a pinch, and than sorted out the issue by in large (although I would say and like to hear from any masthead Figaro owners, if the boat is a low and fast pointer rather than sticking its nose into the wind like say a J boat or a Corby)

Now you have the mindset, i will let you find out how to tune the fore-aft triangle and adjust the shrouds on the sides and any other controls like chocks, by refring tunijng guides, your sailmaker or someone who is expert in your type of boat.

2) Running Rigging And Sail Trim

On most boats there is one piece of rigging which is part of the standing rigging more or less, but is actually runnijng rigging ie adustable underway, and that is  the backstay. (,fancy boats may habe hydraulic forestays or mast rams adjustable underway)

On all boats really, tightening te backstay underrway will increase the rake by taking up slack in the forestay, and the whole mast pivots around its base or a low point at least, 'in column' as the say After this point when the forestay is taught, the backstay will induce bend in the mast like pulling a bowstring. Inducing bend flattens the sail and opens the leech, but also can move the COE further back a little more as it does so, than was achieved at maximum pivoting ie rake.

Opening the leech though means that the top of the sail 'falls off' and the lever pushing the boat to windward is reduced disporoportuionately to the sail area up there, because there is always a higher wind velocity up there, wind exerts force increasing by its cube, and the sail is a little more twisted usually before you open it more, creating a power vector pointing further forward than the lower sail- all of which basically mean that the top third of the sail does more than a third of the effort in 'twistng' the boat round its keel as a pivot in the water, and upto windward when close hauled.

The mainsail produces this 'weather helm' which is at its most noticeable when you broach on a reach, or when it is windy and you do not ge your foresail trimmed in quickly coming out a tack, or when of course, you are overpowered and need to twist the sail off to depower the top.

Exacerbating weather helm on many 'tonne' dericed racing yachts, especially the David Thomas series from the 1970s, is particular hull shape where more heel makes a lot more weather helm as te boat heels, gains a loknger water line on the lee side and wants to roundbup to windward.

Also here we getinto the realms of leeway and what VMG really means. See the note below basicaøly though, the bearing the bow points at on the beat in a keel boat or older dinghy is not quite the actual vector. Leeway increases drastically when flow is detached from the keel and rudder on  beat, so not going fast enough, heeling toomuch, or being screwed up to windward and oscillating all serve to let the boat slip sideways, despite the bow 'pointing' admirably high!

So backstay helps controll the rake underway, and also reduces weather helm after the mast begins to be bent. Many designs of sail boat benefit from very active use of the backstay, it beijng trimmed often as much as the mainsheet and maybe more, because thw effects of moving upb to optimal rake, and being able to then open the top of the sail while the lower two thirds are still driving hard is the best method for that boat in given conditions.

Now you are left with sail trim amd the key control esåpecially on fractional rigs is the mainsheet, whic most people can get right if they have tell tales ! In lighter winds on many boats say underr 6 knts, it can be best for VMG on the beat, the true meausre of gopd pointing, tonlet the top tell tale fly 90%+ of the time, then at 6-14 knits say, flying 75%, 16-22 50% and higher speeds flying over 90% again.

The final judgement is down then to the feel of the loading on the helm and yourbtagret speed verus other boats or on the dials. A lot of modern boats have very neutral rudders when pointing optimally at best VMG, whilenoøder deaigns often need more than 5 degrees of rudder angle pulled on to be giving optimal VMG. Many top racing boats either keep a very close eye on the competiton or if they have instruments use them to check boat speed against a polar chart-look this and VMG up yourself via googling or in books.

Jib-genoa cannot be forgotten. They counter balance the weather helm lever effect by levering the othernside of the pivot point down the keel (The CLR) , YET  they power up the main sail such that the main produces more weather helm.  Too much power can come from too big a sail if there is a wardrobe of sails, or that the sail is tpo deep and too 'hooked' in on the leech- it needs twisting off or changing down to a smaller sail.

This is all within the scope of other sail-tuning guides, books, googling....but the one comment I will add is that the jib cars are often at arbitary lateral positions on the deck on cruiser racers, or placed at a conpromise on some race boats even. Then you have the opportunity to explore in-hauling or even out-hauling the sail in order to power up the main in a narrower slot, or depower by widening it. They work in the same way the traveller altera the angle of the main sail.

To make a point relating to my blog on key areas: very often the main issue with pointing is that you have not spottes or executes thwe right gear change, or in reaspect of rig and sail teim knowledge, you have started out in the wrong gear.

The most common single problem i have seen on boats with relatively poor pointing in getting the gear right before sailing, is too short a forestay setting thua not enough rake in thw mast. Conversely, too long a setting for the wind conditions will open up te top of the mai too much and ruin pointing.
main issue with pointing

3) skills and Style of Boat And Sailing

In terms of skill combined with style of sailing requireed to make a specific boat point optomally, a key thing to learn is speed-before-height. You have to reach a high enough boat speed for your foils to be 'flying' in the water ( keel and rudder, not hydro-foils !) beforee you can then ease the boat up to highest pointing.

Another style element is steering more or holding a course more and sheeting. This is a bit of an art form more than anything else, but in an OD fleet you will see a domijnant, successful methodology and in my experience it is a combination which varies with the wind stregnth. It is very mucb an experience oriented thing though. Worth itas own blog, and in terms of pointing issues, much of this is actually avoided by covering rig tune and gear changes, which shouild reduce the amoint of trimmijng to be done, or make that trimmijng more effective.

Finally some boats just do not like to be pointed very high....any high performamce upwind p,abijng dijnghy, some heavy boats and some light sporty boats. Take the j92 for example, it has better VMG when the bow is pointinng lower. As mentioned above, a lot of this is to do wit what is happening out of sight, with the keel and rudder known togwter as the "foils."  hullshape also has a part to llay, along with overall sailplan and the pivot centre (CLR). The j92 is a very good example becasuse it i mostly saiøed in handicap fleets aginst hweavier, cruiser-racers, and it needs to have a lower angle than rival boats because VMG is then optmal. It is much easier in a one design fleet to see what style pays, but even then you may need to adjust to the weignt you carry beinv eigber asode of the fleet norm.