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Roly Gardner
13th July 2009, 07:25 PM
Hi Roger, Hi All,

I have not posted for a little while as things have been moving forward OK. I am now comfortable in the straps and harness and have even managed to waterstart, although I am far from competent. I still have problems getting the rig to fly. particularly if it is choppy.

Anyway, my query relates to bearing away when powered up. I sail on the coast and it can get a bit choppy. I was out yesterday in 20 mph winds, a bit gusty but OK, on my 145 Carve, 44cm fin and 5.8m Gaastra Manic rig.

I found that the board was heading straight into wind at every opportunity and that it took all my strength to bear away and head off on a beam reach. I was trying to get as low as possible and use mfp to drive off my front foot if that makes any sense. This did work OK but I found that once planing when I tried to get in the straps and harness the tendancy was to head to close to wind and I lost speed.

I have seen other sailors adopting good "super 7" stances with the rig seemingly sheeted in hard and they do not seem to have this problem. Should I try to steer with my feet rather than the rig? I wonder if I need to pull the mast more upright or even across my body more when trying to head off the wind? I assume that the usual rules apply in terms of rig back to head up and rig forward to bear away. I think that I may be adopting a bad body position which is inadvertently shifting the rig, I am not sure. I would be interested to learn how the board's direction can be controlled with the feet.

Thank you in advance.

Roly

Roger
14th July 2009, 07:21 AM
Hi Roly,
Hmmmm.... I forget.... did you used to sail longboards or did you ride a Start w centerboard or something before your Carve 145?
If you are now fully planing, in both footstraps, and have your rig raked back nearly until the foot is parallel with the deck of your board, you should really find yourself "suspended" from the rig.
There would be almost no weight on either of your feet, and you cannot get MFP (Mast Foot Pressure) by pushing forward or down with your front foot.
All your weight needs to be committed to the rig, and you will have virtually no weight on the back of your board.
So, fully planing on a powered up rig means you have to totally steer your board with your feet.
Be sure that you do not have the upwind rail lower than the leeward rail. This would make your board want to "round up" in a heartbeat.
Your board needs to be perfectly flat on the water (to go straight ahead....fast).
There are 2 ways to go upwind when you are all lit up and powered up.
The slow way.... by tipping the upwind rail down some and letting the rocker in your board pull you upwind.... this creates a lot of unnecessary drag which is why it's slow.
Or get all your weight on the rig and pull up slightly with your front foot while pushing across the top of the fin. This is the FASTER way upwnd when fully planing.
It's very counterintuitive... but what you are doing is canting the fin so the root is a bit down wind of the tip and the fin can actually "fly" your board slightly.
Now... back to your original question.....
If you are "rounding up" there are only 2 things you could be doing that would cause this.
1/ You have too much weight on your front foot or on your rear heel and are actually tipping the upwind rail down a little. You can tell is this is happening by looking at the spray coming from under your planing board.
If the spray is mostly coming from under the lee rail and going down wind, guess what, you are tipping your board upwind.
If most of the spray is coming out from under your board on the upwind side, and the waterline is back to the front upwind footstrap you have it right. You will see only green water along the lee rail.
Or if you are on a reach, and you truly have your board flat on the water, the spray will come out from at or behind the fornt footstraps and be pretty equal both on the upwind and downwind sides of the tail of your board.
2/ You are over raking your rig.
The idea behind planing fast, balancing rig size with fin size and a few other tuning issues is to get the CLR (center of lateral resistance) of the fin to balance with the CE (Center of effort) in your sail.
When you get everything tuned correctly, you should achieve this balance when the rig is raked back until the foot angle on the sail is parallel with the deck of your board.
If you have the rig fairly far back in the mast slot, you can actually get the CE behind the CLR and your board will tend to "round up".
With your smaller 5.8 m2 sail, it's quite possible the foot angle is cut pretty high, so if you try to rake your rig back until the foot angle is parallel, you have the rig raked back too far.
How to correct for this?
When you want to head more downwind, unrake your rig very slightly and maybe open it up slightly as well.
I've watched the pro level formula racers try to head off downwind, and while you may not get many of them to admit it, they all slightly unrake their rigs to really head far off the wind. They also do not sheet the rig down quite as hard on the deck unless they are really powered up.
So, I think my message here is that you have now "graduated" to a short board, and other than changing the rake angle very slightly, almost all of your steering is done with your legs and feet, but remember, there should be virtually no weight on them.
Hope this helps,

johntr
14th July 2009, 09:27 AM
Roger:

Is there a "typo" here?

You can tell is this is happening by looking at the spray coming from under your planing board.
If the spray is mostly coming from under the lee rail and going down wind, guess what, you are tipping your board upwind.
If most of the spray is coming out from under your board on the upwind side, and the waterline is back to the front upwind footstrap you have it right. You will see only green water along the lee rail.

Seems to me that when I'm flying upwind driving off the fin, I have spray flying off the downwind side of the board (away from me), and the water directly under my feet is mostly clear and green. (I usually sail with the board very slightly tilted away from me when fully powered up, or completely flat if I'm going across wind and really working on speed.)

John

Roger
14th July 2009, 10:41 AM
Hi Johntr,
Hmmm.... No typo!
If the spray is coming out on the downwind side, the board has to be tipped upwind.
If the lee rail is lowered and you are "on the fin" the lee rail will seal against the water
and prevent any spray on the downwind side.
All the spray would then come out under the board and upwind.
Think about this a little more and take another look next time you are planing.
If your board is truly flat to the water then the spray will be divided fairly equally
but a better indicator is where the water exits. If it's even under both footstraps, then
the board is flat.
If not then the lower rail will have the rail buried further forward.
Hope this helps,

Roly Gardner
14th July 2009, 09:47 PM
Hi Roger,

Thank you for your lengthy reply and explanation.

Just to re cap, I learnt to sail 3 years ago on a club hire board, 200 ltrs with a dagger board. This is my 3rd season on the Carve 145. I sail on the coast which can be quite windy and choppy.

In terms of kit, I have a 5.8m Manic, 6.5m Pilot and 7.8m Lightening which I rig on either 4.30 or 4.60 mast both of which are 75% carbon. My fin choice is either the original 52cm which has a fairly straight profile or a 44cm which has a slightly curved profile.

Do you think that the 52cm fin is best for the largest of the 3 sails and the 44cm best for the other two?

I note from your post that you talk about the mast foot track and the position of the uj. I have recently measured from the tail of the board to 135 cm as I read somewhere that this was a good starting point. To me, this seemed quite a long way back on the my board certainly further back than I had been used to. I wonder if this might have an effect. Is this also dependent upon which sail I am using and even which fin?

The two main issues you identify are also ringing true to me. I am sure that I am trying to get out on the windward rail too early in an effort to get into the straps which are in the outer most positions. Presumably I should be waiting until the rig is more powered up to offset my feet position and oppose the rig whilst keeping the deck flat.

The second point is also something that confuses me. I felt that raking the rig back, which is something I see other sailors doing and try to emulate, is actually moving the CE too far back and thus driving the board upwind. Does this also suggest that the mast foot is too far back in the mast track perhaps? When you say "raking the rig back" does this actually involve bringing the mast off vertical or is it more pulling down on the boom? Again, to me this action seems to be steering the board upwind. Is there something that I should be doing to compensate?

Finally, when you say that the steering once planing is with the feet, do you mean that I am trying to either push the nose of the board off wind by pushing on my front foot and pulling on my back foot and vice versa? Or is it more "toes and heals" altering the tilt of the board to the water and thus the direction?

As always, thank you for your help.

Roly

johntr
15th July 2009, 02:26 AM
Roger:

Interesting. I'll have to watch closely where the spray is coming from. When I'm fully locked in the harness and straps, and driving hard upwind, the spray exits at the footstraps on both sides ... but there's some additional spray coming off the board or fin on the downwind side. It's not the usual solid spray, but some additional white and frothy stuff, and my memory is that it's off the very rear of the board. (The reason I know is that I've been thinking for a while that it's a sign of an inefficiency somewhere, but I haven't yet found anything to do to get rid of it. There's less -- or perhaps none -- when I'm going more across the wind, but when I drive hard on the fin with my back foot I always get some froth off the downwind side.)

I'll watch more carefully next time I sail.

Roly: I don't totally understand the physics, but as Roger says, when you're really locked and flying, you bring the whole rig back with you. If you do this too early, you'll turn upwind. You have to think of the process as happening in steps, with each step waiting on completion of the prior step.

John

Roger
15th July 2009, 06:08 AM
Just to re cap, I learnt to sail 3 years ago on a club hire board, 200 ltrs with a dagger board. This is my 3rd season on the Carve 145. I sail on the coast which can be quite windy and choppy.
OK, maybe you remember "rig steering" (forward with the rig takes you downwind....back with the rig takes you upwind..) from your early days on the trainer board.
You can still steer your Carve 145 by raking the rig forward and back, but it will not respond the way that a board with a centerboard will as you cannot really get the rig forward of or behind the single rear fin the way you can move the CE of the sail fore and aft of the CLR of a centerboard (fixed or pivoting).

In terms of kit, I have a 5.8m Manic, 6.5m Pilot and 7.8m Lightening which I rig on either 4.30 or 4.60 mast both of which are 75% carbon. My fin choice is either the original 52cm which has a fairly straight profile or a 44cm which has a slightly curved profile.

I would guess the 52 cm is marginally large enough. A bigger fin in the 56-60 cm range would probably get you planing much earlier and help with getting you upwind when you learn to sail "on the fin". Use the 56-60 with your 7.8 m2 or larger rigs.
Use the 52 cm for your 6.5 m2 and the 44 cm fin should be OK for your 5.8 m2.

Do you think that the 52cm fin is best for the largest of the 3 sails and the 44cm best for the other two?

No, I'd suggest a larger fin for your larger 7.8 Tush Lightningsail, the 52 cm for your 6.5 m2 Pilot, and the 44cm for your 5.8 m2 Manic.

I note from your post that you talk about the mast foot track and the position of the uj. I have recently measured from the tail of the board to 135 cm as I read somewhere that this was a good starting point. To me, this seemed quite a long way back on the my board certainly further back than I had been used to. I wonder if this might have an effect. Is this also dependent upon which sail I am using and even which fin?

Mast foot positioning is a very important tuning parameter.
Yes, it might change with sail size and/or fin size, but it's always a "tuning" item.
Most boards have a "sweet spot" where everything works and is well balanced. Your board will be fast and stable.
I cannot tell you where the "sweet spot" is on the Carve 145. It might actually be at
135 cm from the tail, but I look on these "guidelines" as being the right place for whatever "expert" came up with the recommendation, on their board, in their conditions, with their fins and sails.
It's never that easy, and you really need to move the mast foot both behind 135 cm and ahead of 135 cm to find out the differences in speed and smoothness of ride.
Where you apply the mast foot pressure on your board is a function of the rocker line in the board, your stance, your fins, and your sails.
You might find alot more speed with the mast foot further back. And you could turn your easy riding Carve 145 into a "bucking bronco" if you get the MFP too far forward and your board goes into a bound and rebound cycle.
You simply have to experiment and come up with the best position for your setup in your conditions.... maybe even "each of your setups" in your various condtions with various sails and fins.

The two main issues you identify are also ringing true to me. I am sure that I am trying to get out on the windward rail too early in an effort to get into the straps which are in the outer most positions. Presumably I should be waiting until the rig is more powered up to offset my feet position and oppose the rig whilst keeping the deck flat.
Yes, moving back too early, moving outboard too early, and raking your rig back too soon can all lead to "rounding up" individually, and if you combine a couple of them you really have a rounding up problem.
Only move back at a rate that keeps your board accellerating.
Only move fully outboard when you can get hooked in so the rig can take all your weight.
Only rake the sail fully back and in when you have the speed and you are fully hooked in and in the footstraps. Otherwise, your sail will make more power, and prevent your from rounding up, if you keep it a little more open with less rake.

The second point is also something that confuses me. I felt that raking the rig back, which is something I see other sailors doing and try to emulate, is actually moving the CE too far back and thus driving the board upwind. Does this also suggest that the mast foot is too far back in the mast track perhaps? When you say "raking the rig back" does this actually involve bringing the mast off vertical or is it more pulling down on the boom? Again, to me this action seems to be steering the board upwind. Is there something that I should be doing to compensate?

Hmmmm... lots of really "dynamic" tuning issues to address in this paragraph.
First, get the mast foot in the "sweet spot" where your board planes easily and fast with
good control. Do not move thei mast foot so far forward that you have "complete control" but the board is rattling over the chop. This leads to bound and rebound and will rattle your teeth in addition to being quite slow.
You want the mast foot back enough so the board really planes freely and maybe is a little on the "verge of control".
Moving the mast foot forward will virtually always "slow" your board (unless it's a formula board and you want max. VMG upwind). Moving it back will almost always make your board faster but as it gets faster, you begin to get on the verge of control.
Full control is pretty slow, out of control is also pretty slow. So you need to find the sweet spot where you have "just enough" control to be comfortable, but the board is really fast and lively.
Next is raking your rig back.
With your 6.5 and 7.8n m2 rigs, I would suspect the foot angle will pretty much prevent you from raking your rig too far back unless you have it rigged too high off the deck.
Ideally, when you rake your rig back the entire foot angle will touch the deck at about the same time/angle and it will "endplate" (called closing the gap) on the deck of your board.
Your 5.8 m2 Manic may be cut a bit higher so it would be pretty easy to rake it back too far and tend to drive your board upwind.
As far as "do you pull the rig down with the boom" or "bring the mast off vertical" you really do neither, or perhaps both.
You should never really pull UP or Down on your boom, although some sailors say they "hang' from their booms some of the time.
The power in the sail holds the rig up, and you resist that force with your harness and harness lines. In the bargain, your weight is mostly "absorbed or lifted" off the board by the power in your rig.
When everything is tuned and balanced, you have virtually no weight on your feet, the rig is not jerking you around or up off your feet. You simply resist all the forces in the rig with your weight cantilevered out off the harness line.
So, as you move back on th board as it accelerates, your bring the rig back with your, but slowly and progressively. When the rig is raked back enough and you are near the front foot strap, it's a good time to put your front foot in the strap and hook in to your harness.
Then as the rig takes your weight, you can put a little weight on the front foot momentarily while getting into the back strap.
Wait, with all your weight on the back foot and leg with your rear foot ahead of the rear footstraps and on the centerline of the board, until you are hooked in and stable in the front footstrap. NOW you are ready to get in the back strap and begin to sheet the sail in and the foot angle raking back and down on the deck.

Finally, when you say that the steering once planing is with the feet, do you mean that I am trying to either push the nose of the board off wind by pushing on my front foot and pulling on my back foot and vice versa? Or is it more "toes and heals" altering the tilt of the board to the water and thus the direction?

Mostly is tipping the board slightly by levering up with your arches to go downwind, or pressing down on your heels (by flexing your ankles) to go upwind in slow mode.
Fast mode upwind is tipping your board slightly downwind, but lifting with your front foot and at the same time pushing pretty hard across the top of the fin with your back foot.

As always, thank you for your help.
As always, you are very welcome. It's a pleasure to hear that you are making progress.

Roger
15th July 2009, 06:25 AM
Hi Johntr,
I've pasted in your post here:
"Interesting. I'll have to watch closely where the spray is coming from. When I'm fully locked in the harness and straps, and driving hard upwind, the spray exits at the footstraps on both sides ... but there's some additional spray coming off the board or fin on the downwind side.
Try rolling your board a little more and see what happens.
On a 94 c, wide board, with a big rig like yours, and a full 62-70 cm formula fin, or a 40 cm or larger weed fin, I often have the entire upwind rail off the water and you can see splashes coming out from under the board. Also, the point at which the board touches the water is further forward on the downwind side. It's almost like you are sailing on the downwind half of the board.

It's not the usual solid spray, but some additional white and frothy stuff, and my memory is that it's off the very rear of the board. (The reason I know is that I've been thinking for a while that it's a sign of an inefficiency somewhere, but I haven't yet found anything to do to get rid of it.
Maybe you are just "pushing too hard"! Try backing off slightly on the "push across the top of the fin" and see if your speed doesn't come up a bit without a major loss in upwnd angle. You always have to play speed against angle when going upwind "on the fin".
There's less -- or perhaps none -- when I'm going more across the wind, but when I drive hard on the fin with my back foot I always get some froth off the downwind side.)
Maybe it's just something about the rear rail on your BIC Techno Formula (don't think I've ever sailed one of those) that causes the splash.
On Starboard formulas, Free Formulas, older Starts and F-Types as well as the larger iSonics, there's splash to lee behind the board, and some along the rail over chop, but mostly green clear water down the rail between the front and rear footstraps on the lee side.
Hope this helps!