Here is how I am doing that (wrong)
and there example how it suppose to be ( good)
I suspect that I loose quite a lot of my 8.0 m2 sail performance by the incompetence to close the gap.
But how to do it ?
Is it the harness thing ( I use waist not seat) ?
or harness lines ?
How to close that gap easy ?
I think the modern understanding is that 'closing the gap' is not what it used to be.
Your sail looks like it doesn't have quite the same cut as the other two sails you show. Yours seems to have a higher foot versus the lower/fuller foot of the slalom/race sails you show.
PS: is that Kato with the darth helmet and green Carbon Art?
I've noticed one difference in the pics, you have front hand over the boom the other 2 have front hand under. It's not going to be the whole answer, but with the sail raked back I find it more comfortable using a underhand grip at the front.
Moving the mast base forward, or footstraps back may also help.
Some observations..
Your board trim angle it too obtuse - nose very high. Look at fin selection and fore/aft footstrap positions. Not enough lift from fin, straps too far back = insufficient mast foot pressure.
It may not be those things alone - to me you sail looks like there may be an issue with the mast or downhaul/leech tension.
I could be totally off the mark but it looks like you are pretty uncomfortable there.. Try moving your front straps forward an inch and if not enough, the back straps- for light wind
Of course all this could be rubbish..I cant see what board is is or what fin you have
I did notice in some of the picks your sail is rigged high on your extension.
I agree looking at that photo it does look like a mast mismatch or downhaul setting problem.
are you using the right mast and the correct length extension/mast for the luff? is it downhauled to spec?
Not enough downhaul in that first picture, look at batten 4 and 5, the batten tip is pressing out the luff sleeve ( or is it the cam over rotating?) whichever it is showing the leading edge of the luff inside the sleeve is around to the side of the mast too much, needs more downhaul to pull it around behind.
Probably doing it in the bottom picture as well as the sail looks very full in the leading edge up high. I imagine the sail has lots of pull but gets pretty heavy and you start wrestling with it as it powers up???? if so that is one of the reasons you are having trouble locking in to a comfortable stance.
Same as what mr love said. Sail looks like it needs needs more down haul, the sail looks like its not venting and pulling you on to your toe's preventing you from fully sheeting in (hence high nose). 
On that day ( I am not sure if I am doing that right) , because of very light winds,
indeed I did apply minimal down haul and minimal / neutral out haul.
From my observations that create maximum size belly in that sail and top is in fact quite stiff.
Because of light winds 15- 17 knots if wasn't much problem , wind at Burrum was extremely stable without any sudden gusts - that helps also.
Mast indeed is pretty random , may not be ideal for the sail.
Board used was JP Slalom 68 cm wide (118 L ) and fin BP 37.5
Definitely due to my lack of technique or wrong setup ( or both) I was slower by 2-3 knots on NM in comparison to top performers on the day, but we had very similar sail size.
Same day, same event place and wind, but other guy been able to close the gap completely 
Legs ?
I found that most of the time my back leg is straight and front is bent.
On the pictures of good sailors I could see that opposite is true. They have back leg bent and front straight.
Why is that ?
In very general terms back leg straight front leg bent when going upwind
back leg bent front leg straight when going downwind.
there are exceptions like people that like to drive the tail of their board
you could be definitely be onto something.
You are not going to be able to close the gap completely like on the Overdrive as it looks like your GTX is cut with a higher foot angle. Generally speaking true race sails have a low foot angle and the 'freerace / freeride " sails have it a bit higher.
Select to expand quotemr love said..
You are not going to be able to close the gap completely like on the Overdrive as it looks like your GTX is cut with a higher foot angle. Generally speaking true race sails have a low foot angle and the 'freerace / freeride " sails have it a bit higher.
Agreed. You can see that the foot is higher and the GTX is described as a free-ride/free-race sail.
You can see the shape of the sail here:
and
I think there is only one thing to do.
we should all go back there again next year and work on our stances. 
Peter i believe there are a bunch of problems starting with
Down Haul: You need more, minimal down haul my feil powerful but it is hard to control and you will not accelerate in the gusts.
Boom Height: you run your boom above eye level, this is different to everything i have read. ( try your boom around chin height) it may feil odd at first but you will get comfortable in time
Fin size: 37.5 fin with a 8m is quite small a larger fin will create more lift, the board will sit better.
This is just my opinion.
I reckon your harness hook is too high as well. Looking at the first pics, your harness is mid chest, Kato's is on his hips. You need your harness hook low so you can commit to the harness, which generates more mast foot pressure, which in turn will enable you to sheet in more & better. Plus add the rigging stuff in that Martin and others mentioned - correct down haul is so so important.
Listen to these guys about tuning the rig, and possibly finding the right fin between 38-40cm. If you still feel you are front leg bent too much, then it may be that foot straps need to inch forward.
The hardest thing is having the patience to do all your adjustments incrementally and recording it all so you can keep track and not 'miss a trick'.
Ahh the joys of tuning
What everyone else has said PLUS your wearing a waste harness. Buy a kite and join us. We don't close any gaps.
You'll master kiting in a day - simples.
Windsurfing requires talent and dedication.
Select to expand quoteKitepro said..
What everyone else has said PLUS your wearing a waste harness. Buy a kite and join us. We don't close any gaps.
You'll master kiting in a day - simples.
Windsurfing requires talent and dedication.
Yeah what kitepro said!!! You should do kiting cause we are so much more extreme!! Windsurfing is from the 80's anyway.
Rock on cause kiting is so sic!!
The bottom line is that the centre of lift of the sail has to be lined up opposite the centre of the hydrodynamic lift created by the board. Otherwise you'll turn a corner.
You look like you're riding off the fin, not off a sunken windward rail, so the centre of hydrodynamic lift is pretty well at the fin. So there's not much you can do other than alter the aerodynamics of the sail. More downhaul could move the centre of lift of the sail forward, which means you'll then have to rake it back further to sail a straight line. Or move the mast track forward, that'll also force you to rake the sail back to keep things in balance. Maybe you're over-sheeting? That would move the centre of lift back in the sail and force you to keep it more upright.
Or, if the fin's movable, move it back. The sail will have to follow.
I thought "closing the gap" was not considered all that important any more?
fairly certain the Chinese invented kites in the 5th century but whatev's 
Hey Peter maybe pop over to my place and we'll rig that Gaastra on one of my enigmas and see if it will work, gimmie a ring
Curt, if its a 490 he needs Peter can use mine, let me know when your heading over to Curts and ill come overas well
Select to expand quoteGestalt said..
looking at photos from the previous day peter your rig and stance looks good.
Reckon Macro could move his arms further apart.. front hands not quite touching the mast
I wasn't trawling. dunkerbeck is known for his wide grip. not trying to prove you wrong at all but you should accept that in speed sailing the stances are varied across the board. some stances just look wrong and yet the guys are capable of doing over 40 knots regularly.
macro has come here looking for help. his stance is directly tied into how his sail is rigged which is why people are trying to help him with rigging. he rigged his sail on the day to suit the wind which was light. the result is he's not completely happy with it. in that photo it would be lucky to be 12 knots.
the choice is your's.
you can offer advice,
or you can continue to be sarcastic towards others. we're not at kindy anymore barn.
I believe what you are reffering to is what we use to call closing the shot. This was back in the 90's though.
Looks like your harness lines are too long (ask Rolz he still rund 12" lines with a seat harness) and your not leaning your sail back far enough.
I prefer to have my sail upright and out infront of me to catch more wind. If the sail is behind you then you will be going backwards. Put it out more infront of you to catch the wind and go faster. Thats how the SWAT Team get it done!!!
Select to expand quoteremo81 said..
I believe what you are reffering to is what we use to call closing the shot. This was back in the 90's though.
Looks like your harness lines are too long (ask Rolz he still rund 12" lines with a seat harness) and your not leaning your sail back far enough.
I prefer to have my sail upright and out infront of me to catch more wind. If the sail is behind you then you will be going backwards. Put it out more infront of you to catch the wind and go faster. Thats how the SWAT Team get it done!!!
You say shot, I say slot.
It's all the same 
Boom between shoulder and chin.
Change to seat harness (Dakine Fusions are good with a moderate hook height and back support) for slalom and freeride sailing.
Fit 28 inch harness lines.
No need to spread arms so far apart if lines are set properly. Ideally shoulder width apart.
Under hand grip on front hand except when water starting.
Always start with max downhaul and then work backwards.
Use as little extension as possible to get max downhaul (I am always block-to-block at max).
Measure your boom to check the length you're setting it at.
Try to set boom length so there is no gap between clew and tailpiece when outhaul is set correctly.
Do not over-outhaul.
Bigger fin for bigger sails.
Rear strap should be in the middle of it's fore-aft adjustment (not all the way back).
Your sail isn't designed to sweep the deck like a race sail so don't worry about that too much. It has a higher clew to help you out in rough water.
Finally, if you really want make your life easy and have more fun - go camless!
Select to expand quoteGestalt said..
I wasn't trawling. dunkerbeck is known for his wide grip. not trying to prove you wrong at all but you should accept that in speed sailing the stances are varied across the board. some stances just look wrong and yet the guys are capable of doing over 40 knots regularly.
macro has come here looking for help. his stance is directly tied into how his sail is rigged which is why people are trying to help him with rigging. he rigged his sail on the day to suit the wind which was light. the result is he's not completely happy with it. in that photo it would be lucky to be 12 knots.
the choice is your's.
you can offer advice,
or you can continue to be sarcastic towards others. we're not at kindy anymore barn.
We're not in kindy, everyone's getting old, fast! We don't have time to pussyfoot around!
I've done my time correcting peoples stance, it's a full time job. I'm as qualified as it comes. The easiest way to fix somebodies stance is to make them accept they're doing everything wrong.. Especially if they're as stubborn as Macro..
A great way to improve someones sailing is to make them watch a video of themselves in front of an audience of other windsurfers. Sit down, get the pause button out, and dissect their session frame by frame.. When someone witnesses their mates having a chuckle at their mistakes, the next day, they're on the water and they try harder than ever to change..
Regarding his equipment being the root of all his stance issues, I bet the Black Power Ranger (aka kato) could still manage that textbook stance on the exact same kit, even if it is rigged like a dogs breakfast..
Select to expand quoteGestalt said..
I think there is only one thing to do.
we should all go back there again next year and work on our stances.
That is actually very good idea. This year Kato has very informative presentation about speed sailing in general.
Next year we could run a speed clinic one day to learn and find out what we could improve in our stance and speed sailing.
