Leeboards

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Alm

Re: Leeboards

Post by Alm »

mussopo wrote: Thus, may i understand you're controlling main sheet without a cleat (bungee working as shock absorber)?
In "motor-sailing", yes. Just tie some easy knot around the deck bungee. This bungee has more "intuition" than me - it is stretching when wind suddenly become stronger for a few seconds and returns to more relaxed position when wind slows down. Kind of low-tech automatic "cruise control". I'm doing this only for motor-sailing in very light winds. In heavy winds the line should be in your hands. The only exception (when I tie the line to the bungee during winds stronger than 10 knots) is when I have to pee on a long passage and don't want to stop completely, and then I let the sail out a little, so the speed is slower, and tie the line to the bungee. $5 folding bucket carried on deck as a bailing device serves this purpose perfect, as I've found.

Another thing to remember with aft mast is that control line may escape from your hands and then you can't reach it in a single kayak until you land. To avoid this, I made the line a little longer, tied a clip to the end, and clip it (not cleat it) to the D-ring in front of me at all times.

Alm

Re: Leeboards

Post by Alm »

john allsop wrote:In the first question "Treecutter" informed us that he was using a Lateen sail, isn,t this sail considered to be quite good at "going up wind" as regards the written word, the book by Todd E Bradshaw "Canoe Rig, The Essence and the Art" .
Nice book, nice pictures, too "classic" for those who just want a simple ready-made sail rig. For understanding the basics the book Sail Your Canoe by John Bull in my opinion is better, more concise.
Upwind performance of Lateen sail is one thing, and Lateral Resistance - another. Well performing upwind sail provides a lot of upwind "lift", in other words - faster speed and/or better angle, but with insufficient LR the boat will still slide to the lee side (thus making the resulting course essentially a beam-reach).

Lateen sail is a very old design from ancient Greece or Rome, tried by Columbus. Back in the 15th century it was an improvement over square sails. These days, and for boats with outrigger (or real keel like yachts) other upwind designs work better. One particular problem with Lateen is that there is no easy way to reef it. This might not be important in daytrips, but in wilderness passages when suitable landing spots are few and far in between, this can be dangerous.

Kapitän von Klepper

Re: Leeboards

Post by Kapitän von Klepper »

Alm wrote:When going upwind, you can't judge the optimal trim of sail by looking at tell-tales. Whether the sail is fore or aft of you, your only indicator on upwind course is how tight the control line feels in your hand. And the optimal "tight" depends on how heavy the wind is.

The only thing that I could judge by looking is when sail becomes flapping if the course too close to the wind, but this I can always hear, and it also feels immediately - the boat stalls.

So, eventually I am doing the same thing as if it were fore-mounted sails - tighten the line up to the point that gives me the best speed at the particular course.
If you have your tell tails properly mounted on the luff of the sail, they will stream in a staight line on the same plane from the sail. If the they appear to bend in, your sail is trimmed out too far and you are spilling wind. If bending out, you are trimmed too far in and not taking full advantage of available wind. If you are sailing with a jib this will also effect the telltails. Set your jib first (unfortunately tell tails don't help us here as we kayakers can almost never see the jib when sailing). Let your sheet line out until the sail lufts, that is flaps, then trim it in a nudge. Next set your main until the tell tails stream in a straight line from the sail.

You can get some idea of actual wind from telltails on the shrouds, but the best indicator is the wave pattern.

I don't have any reason to hand hold the sheets unless the wind is particularly gusty. I cleat both sheets in cam cleats. You can use a permenant ink marker to place a ring on your sheet lines so you can accurately find your ideal sheet length. The main advantage of this is that once you find that sweet spot of upwind sailing, you really don't have to guess if you've trimmed your sail too much or if the boat has nudged too much to weather if the sail lufts. If you know your sail is at proper sheet length and the sail luffs, steer slightly to lee until the sail stops luffing, -you would now be on a proper angle to the wind. If your tell tails begin to bend out, then you've corrected too far lee.

If you are making progress for a distant landmark, you shouldn't have to change your sheet length on your main when you tack. Just duck your head when jibbing and let the boom swing over. If you're making regular tacks for a known upwind landmark, your main sheet angles should be the same on either tack. If using a jib, naturally you will have to let the jib fly when you change tacks and cleat its other sheet. This is where your permenant ink marks come in handy. You easily find your mark on the next tack.

Alm

Re: Leeboards

Post by Alm »

Kapitän von Klepper wrote:You can use a permenant ink marker to place a ring on your sheet lines so you can accurately find your ideal sheet length. The main advantage of this is that once you find that sweet spot of upwind sailing, you really don't have to guess if you've trimmed your sail too much or if the boat has nudged too much to weather if the sail lufts.
When wind shifts from upwind to beam-reach and to down-wind (because you rounded the point, or changed the course, or wind changed by itself) there is no more permanent marked "sweet spot" and sheets have to be trimmed differently (especially since wind force almost always changes on such occasions). Or when wind is roughly beam reach, but it's shifting around, changing from upwind to beam reach to downwind and back again. In moderate and heavy winds it's always shifting (doesn't matter if it's downwind or upwind course), because waves are pushing you to one side or another. Except for a few reasons like motor-sailing, eating, working with map and GPS, or when you have a second mast with one more control line, - except for those occasions, it's better to keep the line in hand and not to cleat it.
If you are making progress for a distant landmark, you shouldn't have to change your sheet length on your main when you tack. Just duck your head when jibbing and let the boom swing over.

On outrigger FC boats the boom will not swing over to the other side by itself when you're using a main-sail only, unless sail is too large for a give boat. Tacks will require paddle assistance.

Kapitän von Klepper

Re: Leeboards

Post by Kapitän von Klepper »

Alm wrote:When wind changes from upwind to cross-wind and to down-wind (because you rounded the point, or changed the course, or wind changed by itself) there is no more permanent marked "sweet spot" and sheets have to be trimmed differently (especially since wind force almost always changes on such occasions).
I mean if you're trying to find that 45 degrees into the wind... :roll: If you are sailing 45 degrees into the wind, you don't want to cleat your sheet too short (too long and it will luff). If you attempt to sail closer to the wind than your configuaration will allow, you will merely stall and make no progress, despite still having straight streaming telltales. This sweet spot is very tricky to find by pure guess work and once you discover where your sheet should be to have your sail set for the proper angle, it will always be the same no matter how hard the wind is blowing, -as long as you are in close haul. (45 degrees). The one variable is that the position of your fairlead may change to control the foil of the sail. Marking the sheet is not only recommended by top racers, it is the only way to fly.

Obviously if you change your point of sail, you will change your sheet length. Again you can use graduated marks on your sheet for various positions between close reach, beam reach, broad reach and running before the wind. Marking is just the simplest low tech way of taking the guess work out of close haul, -which is so tricky in a kayak anyway.

IF you're using a jib, having both sheets marked (colour coordinated of course) will take the guess work out of trying to find the opposite tack. Instead of taking 30 sec to a minute to guess which is the opposite, you simply cleat on your mark and adjust your rudder until your telltales or luff tell you your actual wind matches your set. If your set was 45 degrees on port tack, then if your marks on your sheet are accurate, your set will be 45 degrees on starboard tack.

Obviously if you're sailing just a main, you have only one sheet. Having your sheet marked for close haul will always ensure that you INSTANTLY find the correct cleat position and you don't have to worry about a stall.
On outrigger FC boats the boom will not swing over to the other side by itself when you're using a main-sail only, unless sail is too large for a give boat. Tacks will require paddle assistance.
Obviously a jibe is a downwind manuver, in which case, the sail will whip overhead, in absence of a boom. Granted an upwind tack through "the irons" will require paddle assist in most cases in a kayak, -I'm still wrestling with this. This is one of the great reasons to have your sheet cleated instead of handheld, -you can paddle into your new tack and your sheet will be ready set, if you are using the same tack angle, which in most cases you will be.

Alm

Re: Leeboards

Post by Alm »

I mean if you're trying to find that 45 degrees into the wind...
Wind seldom blows at 45 degrees to my destination (or 40 degs, or whatever best angle is possible with a given boat-sail-rudder-leeboard envelope at ideal conditions).
Obviously if you change your point of sail, you will change your sheet length. Again you can use graduated marks on your sheet for various positions between close reach, beam reach, broad reach
Looks like I will end up with a few feet of line covered by continuous stretch of graduated marks :-) . Because point of sail changes every time when I change my course. Or - when waves push me off course. Or - when I round the point or approach the shore (wind pattern is always different around points or close to shoreline). I wrote about this, though. Also, close-haul angle opens wider when waves are getting higher. (For this latter reason the closest angle on one side of the tack is not the same as on the other side - because direction of waves doesn't coincide precisely with direction of wind).
If you attempt to sail closer to the wind than your configuaration will allow, you will merely stall and make no progress, despite still having straight streaming telltales.
Correct. This is why I wrote that didn't find telltales useful on upwind course - they are always straight streaming. They are more useful on low-wind downwind course, of course. (In moderate to heavy downwind you usually have enough speed no matter how good or bad the sail is trimmed).
Granted an upwind tack through "the irons" will require paddle assist in most cases in a kayak, -I'm still wrestling with this. This is one of the great reasons to have your sheet cleated instead of handheld,
Yes, this is one more example when cleating makes sense. To do this, I need to find that "sweet spot" that is permanently changing its position depending on the angle of my course to the wind, which in turn requires to hold the line in hand first. And only then (after I have found the optimal trim), I can cleat the line or tie an easy knot on the bungee when approaching the change of tack.

Close-haul upwind course is one more occasion when I often have to do a motor-sailing, because kayaks (and FC in particular) can't come too close to the wind or sail fast enough at this course, so temporary cleating is done often. With motor-sailing not only speed increases, but the angle is getting closer as well - so position of the "sweet spot" changes again. Sometimes I motor-sail on one side of the tack and rest on another, because have to make one side longer than another (for example, I approach the shoreline on one side, and then wind decreases and/or changes the direction).

Perfect "pure sailing" with cleated line and equal angles on each side of the tack probably never happened to me in multiday wilderness tips. When I only have certain landing spots at certain intervals, some daily mileage has to be done, no matter what. Hence, efficiency becomes a higher priority than pure sailing. If paddling (or motor-sailing) gives me a better speed and I am not too tired, then paddling is the way to go. FC boats, and particularly those with aft-mounted mast, are well suited for that - one can always rely on a decent mileage by paddling, even with outrigger in place. There are drawbacks to sailing in FC boats, of course. The better something is to paddle, the less efficient it is to sail (or less enjoyable to sail, or less safe to sail) - and vice versa.

Kapitän von Klepper

Re: Leeboards

Post by Kapitän von Klepper »

Wind seldom blows at 45 degrees to my destination (or 40 degs, or whatever best angle is possible with a given boat-sail-rudder-leeboard envelope at ideal conditions).
But you do sail up wind, don't you? If you sail upwind, and tack, so as to arrive at any destination that is within the 90 degrees of "in the irons" or stall (45 degrees each side of wind direction at 0). You will want to sail as close hauled as your configuration allows. If your destinations NEVER exists in this dead zone, ignore this because you will always be able to get where you're going on anything > close reach. -and must have the luck of the Irish, -May the wind always be at your back.

If your destination lies within 45 degrees of 0, -wind direction, -you are going to want to tack as close hauled as your configuration will allow with out stalling. Let's say your destination exists at 30 degrees of 0, starboard side, 5 miles away. This just means your close hauled port tack legs will be longer than your close hauled starboard legs (the tack names are counter intuitive), but they will be as close to 45 degrees as your configuration will allow.
Looks like I will end up with a few feet of line covered by continuous stretch of graduated marks :-) .
Close haul, close reach, beam reach, broad reach and running, those are the places to mark on your sheet.
Image
Close hauled is the most important because you can't sail closer than close hauled, though your sail may continue to appear full. You will stall, making either no progress, or pitifully slow progress, as the wind pushes you back about just as much as you are going forward.
Because point of sail changes every time when I change my course. Or - when waves push me off course. Or - when I round the point or approach the shore (wind pattern is always different around points or close to shoreline). I wrote about this, though.
This is sort of the point I'm driving at, but if I am genuinely sailing up wind and my destination continues to exist in the "dead area" my tack legs are going to be close hauled, or I will never arrive at my destination.
When rounding points, or approaching shore, wind direction may shift meaning a new point of sail is indicated for that condition. Your destination will not have changed, unless your objective was to get around the point, then of course you have a new heading.
Also, close-haul angle opens wider when waves are getting higher.
This is called leeway. It's the same principal as with a glider. A glider can be pointed to the horizon, but it's going to eventually come to the ground before it gets to the horizon. Wind blowing from your weather side is always going to push you slightly to your lee, -which is the whole purpose behind leeboards, to minimize this. That is why if your genuine destination is at close reach, you may want to sail at close haul so you actually hit your destination without needing tack legs. The stronger the wind, the greater the leeway.
(For this latter reason the closest angle on one side of the tack is not the same as on the other side - because direction of waves doesn't coincide precisely with direction of wind).
No the direction of the waves isn't always precisely with the wind direction it's also affected by currents and tides. This just means that due to leeway, compensation is needed by means of longer opposite tack legs. The point of sail hasn't changed, just the symmetry of the tack legs.
This is why I wrote that didn't find telltales useful on upwind course - they are always straight streaming. They are more useful on low-wind downwind course, of course.
OK, fair enough. This is why I would recommend at least marking your close haul position on your sheet. It will completely eliminate the guess work. Cleat your close haul and then trim your rudder until the tell tails stream straight from your luff. If you have accurately determined your close haul when you marked it before, you will now be at close haul again, -the point of maximum efficient upwind progress.
On downwind sailing, anything broader than a beam reach, the tell tails tend to bend down wind of the luff. They have only marginal value here in determining point of sail.

The rest of what you are saying I concur with. Just as my boat tends to sail differently than a real boat, I imagine a FC may sail differently than a Klepper, -also depending on mast configurations, etc. I'm still tuning my boat to improve performance, with some really great results. I've found kayaks are a great deal more sensitive to tuning than bigger boats. I keep talking about getting a furler for the jib, and I may yet someday.

As far as motor sailing: I've also found this necessary. The problem is that in motor sailing, apparent wind actually begins to effect actual wind. Your sail can be trimmed for pure sailing, but if you paddle, it's going to effect the apparent wind, which will effect the sail trim. So this is a case where the apparent wind you are creating will cause your more efficient point of sail to be boader than 45 degrees of actual wind. To find this new close haul, if you have your sheet marked for close haul, you would simply trim your rudder until the tell tails stream straight from the luff.

Kapitän von Klepper

Re: Leeboards

Post by Kapitän von Klepper »

(The size police wouldn't allow this final paragraph in the above article)
But...
It becomes debatable at what point you might just as well furl the sail and paddle. I generally determine this by wind force. I can sail a lot faster at beam reach than I can ever paddle, even at only force 1. At close haul, I can generally paddle faster than I can sail at force 1. In the San Juans, I find wind can vary so much in the channels (not to mention currents) that I have to do a lot of "motor sailing". If I find that I'm making better headway paddling to my genuine destination inside the dead area, than I am sailing at close haul, I sometimes either strike the sail or reef one and run it up to the top of the mast, -this gives me room to double paddle and sail. This is purely based on conditions since striking the sail may be undesirable if I expect my wind condition to change in the next half mile or so. At some point heading up wind, the sail just creats wind drag and is better struck.

Alm

Re: Leeboards

Post by Alm »

Also, close-haul angle opens wider when waves are getting higher.
This is called leeway.
Leeway is a leeway drift, and it takes place always. What happens in steep waves is that they slow down the forward movement of the boat (while leeway drift due to wind and current remains the same), which results in a wider angle at given speed - or slower speed at a given angle (and then you have to change the angle wider to maintain same speed).

Besides, there are always waves that are pushing the boat randomly off course to either side. Or waves lift the stern and rudder is out of the water, and the course changes again. Besides, in a context of FC sailing, given inadequate rudder arrangements, increase of wind force often results in a situation when rudder can't maintain the same course any more, and then you have to depower the sail and correct the course (and/or change the course), using either a rudder, or a paddle (if the bow is so deep in irons that manipulations with ropes and rudder don't help). As a result, real picture differs from theory.

Kapitän von Klepper

Re: Leeboards

Post by Kapitän von Klepper »

Are you talking about breeches then ? In this case just rudder trim to correct back to close haul when it comes back in contact with the water. What your wave is doing is almost the same as a heavy gust. It just requires quick hands and course correction.

I've never had a situation where port and starboard tacks weren't exactly (except for length) the same and I don't believe I'm a novice. It's the one reliable thing one finds in sailing. Eyeballing is too vague. A marked sheet doesn't lie. If your sheet is cleated on your mark, your tell tails streaming straight, you are making the most efficient upwind progress, no matter what tack... provided you've done your homework. Obviously if your boat isn't symetrical, (lee board or pontoon only on one side), then this would be a physical difference that would effect CR. The CR wouldn't be the same on both tacks. I´m sure this would effect the bearing from tack to tack. This is the boats issue, not the conditions. So I take it back, I have had situations where bearing angle wasn't the same on both tacks, -only when I've failed for one reason or other to switch my leeboards.

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