The trouble with that, it assumes a constant wind direction, could slowy also had a wind shift in the gust, might not be that far downwind?
Completely correct Decrepit, however here's another random session comparison with 7 sailors, same location, same time. Three fastest sailors Slowy, Richo and Woody (all big, strong guys) are sailing deeper than the others. All are unique. Weirdly Antman gets his tops speeds sailing nearly across the wind. SRS73 is oddball but sailed longer so maybe different wind.
Slowy's are more unique and they always seem to have this splintered pattern at the top speeds. Richo seems to be sailing deeper but top speeds are no where near optimal as far as sailing direction. He is also starting to get this splintered pattern like Slowy whatever that means. Woody is perfectionist and always in control. Richo and Slowy more like pushing it to the limit?
Just watching Slowy after what everyone else call the speed run and call it quits, he bears away again into the chop and goes faster. Time stamp 3:18 on latest Rsoles vid I posted or snap shot here, camera shot is back to the wind. 
As newest, least experienced and slowest in GPSTC I cannot advise/clueless what to do, but appears Antman and Richo have biggest potential for big speed increases based only on these polars. So easy to look at these and just say bear away more, but actually doing it is what is hard and addictive.
It is soo addictive bearing off , scary doing it in chop . Getting air off the back of little waves wondering if the fin is going to let go or I'm going into a tank slapper . I think I'm getting close to my limit in those conditions. Maybee a couple more kts 
It must be a pleasure having decent runs on super flat water.
I'm super slow, but when I try bearing off deep like that my sail force drops to almost nothing (and control gets squirrely), but this is also probably on much less windy days? I'm talking 20-25kts or so when I'm on a fin and a 5-6ish sail. And I'm bouncing over the back of chop pretty hard and not going as fast as thedoor.
With those deep runs what is the wind speed like? I can understand apparent wind still being good at 120-130 or so but 160 seems like the wind must have been nuking.
Select to expand quoteaeroegnr said..
I'm super slow, but when I try bearing off deep like that my sail force drops to almost nothing (and control gets squirrely), but this is also probably on much less windy days? I'm talking 20-25kts or so when I'm on a fin and a 5-6ish sail. And I'm bouncing over the back of chop pretty hard and not going as fast as thedoor.
With those deep runs what is the wind speed like? I can understand apparent wind still being good at 120-130 or so but 160 seems like the wind must have been nuking.
If your sail force drops to nothing when you bear away you need a bigger sail for that amount of wind.Either that or only bear away as much as you can to keep pressure in the sail.
It should be hard to handle the power on a reach or upwind. That's why flatwater makes it so much easier.
If you are using a weed fin, you need to move your mast base way back as it doesnt generate as much lift as an upright. You want the board just lightly clipping the top of the chop, not crashing into each wave you go over. It just takes a bit of fine tuning and then when you get the right spot you'll know coz it will feel alot smoother.
Select to expand quoteFlex2 said..
Completely correct Decrepit, however here's another random session comparison with 7 sailors, same location, same time. Three fastest sailors Slowy, Richo and Woody (all big, strong guys) are sailing deeper than the others. All are unique. Weirdly Antman gets his tops speeds sailing nearly across the wind. SRS73 is oddball but sailed longer so maybe different wind.
Slowy's are more unique and they always seem to have this splintered pattern at the top speeds. Richo seems to be sailing deeper but top speeds are no where near optimal as far as sailing direction. He is also starting to get this splintered pattern like Slowy whatever that means. Woody is perfectionist and always in control. Richo and Slowy more like pushing it to the limit?
Just watching Slowy after what everyone else call the speed run and call it quits, he bears away again into the chop and goes faster. Time stamp 3:18 on latest Rsoles vid I posted or snap shot here, camera shot is back to the wind.
Water conditions play a big part in skill levels and this is where Slowie Excels as well as Woody. They are prepared to send it over chop where the board is just on the fin. The big day in the Chook Pond where Slowie hit 47+ knots was a massive gust with a Wind shift, it wasn't smooth water and he held it to the end, with the biggest push coming right at the end.
Another big day was at Albany with most sailors getting PB's for 2 and 5x10 is an example of good water conditions with only a 1-2 knot spread between the sailors who achieved 40+knot, must say Slowie came in late to the action and there was another wind shift from East to North East. I'm not saying theres no skill level in sailing optimal conditions but true skill is making the most of sub optimal conditions which most of us sail in.
If you ever follow slowie on a speed run in Mellville (Good luck keeping up) you'll see he is confident in sending in some narly conditions to get a 40+ speed also how broad he sails is just amazing and in full control. Technique in sailing in non optimal conditions plays a big part as well as having the guts to keep on the gas. Expect a few wipe outs in the quest to master choppy conditions is all i'll say, but the rewards are there albeit that you might go through some gear in your quest
I'd suggest playing your video back at 1/2 speed, then you do go 2s @ 30 knots
I could never go fast deep offwind over chop like that in Poole Harbour as I dont have the bottle. My best speeds were at Portland Harbour where its flatter.
The point of sailing deeper and letting the outhaul off has already been made. When I switched from 3 cam freerace high download tension sails to Ezzy Lion 2 cam I couldnt let the outhaul off like that as the Ezzys need some outhaul. My top speeds dropped as I couldnt sail as deep. My 1 hour times were better though as gybing was easier, better through lulls & sailing was less tiring.
Select to expand quoteAus501 Boz said..
Another big day was at Albany with most sailors getting PB's for 2 and 5x10 is an example of good water conditions with only a 1-2 knot spread between the sailors who achieved 40+knot,
Nice set of polar plots, Boz. The top speeds are shifted towards deeper angles, and 140 degrees was very fast in every plot. That flat Albany water makes it easy to go deep! If that's a typical Albany day, the some of the top speeds were probably in the middle of nautical mile runs, already going deep but then going a but deeper when a big gust hit?
Select to expand quotesboardcrazy said..
If your sail force drops to nothing when you bear away you need a bigger sail for that amount of wind.Either that or only bear away as much as you can to keep pressure in the sail.
What she said. One sail size too small can easily keep you a few knots slower. We had a day at Albany in the spring where I proved that to myself. Very frustrating to be stuck in the mid-30s when you see tons of people hit 40 knots and set PBs.
Another day at Albany was almost as frustrating, but that time, I was on the same sail size as the faster guys of similar weight. That was before I got the lectures from Slowie et al. about how important bagging the sail out for speed runs is (and the tip from Boro about moving the mast foot forward). It was quite fantastic to sail among so many great speed surfers, and get tips on how to go faster.
Another day that I'll remember a long time was at Point Grey, where the usual suspects did 40-42 knots, and Stroppo did 44 or 45 (on a similar sail size, despite and extra 10 or 20 kg of muscle!). I looked at the GPS tracks from that day in detail, and concluded one of Stroppo's secrets was that he started sending it way earlier than everyone else, where the chop was still higher but the wind was cleaner. Almost everyone else waited a bit longer until the water got shallower and flatter, and was slower. Great master class lesson!
Select to expand quoteaeroegnr said..
I'm super slow, but when I try bearing off deep like that my sail force drops to almost nothing (and control gets squirrely), but this is also probably on much less windy days? I'm talking 20-25kts or so when I'm on a fin and a 5-6ish sail. And I'm bouncing over the back of chop pretty hard and not going as fast as thedoor.
With those deep runs what is the wind speed like? I can understand apparent wind still being good at 120-130 or so but 160 seems like the wind must have been nuking.
Quote: "when I try bearing off deep like that my sail force drops to almost nothing (and control gets squirrely)"
This is primarily because the leading edge of your sail is too flat. Think of it this way. The first 30-40% of sail in front of you is where your engine is at, and the horsepower you get out of it is a function of the curve that you rig there.
More curve in your sails leading edge = More horsepower, and also provides a more rounded and user friendly power delivery that is much easier to manage and feels quite noticeably safer and more reliable deep off the wind.
..I've had that feeling you described aerognr ..Most memorably so in a Port - Starboard conflict, in which I was on Port - I instinctively turned away, fairly deep and doing 28 knots. My sail was quite simply too flat and I'd turned way too deep off the wind for it! ..For a second or two I felt that scary "nothing in my sail" feeling, and just as I went over the back of a 1 foot high chop - The nose of my board instantly slapped down the other side of that chop and I had my worst ever catapult. Felt my brain hit the top of my skull and felt like I was going unconscious. For a couple of seconds was truly thinking my number is up.
And so, a full leading edge on your sail also helps you control the position of the nose of your board, as in helps you stop the nose flapping up and down all over the shop in chop. Also makes rail rides over chop more controllable.
have a look at "WA finallly gets some wind" by Flex , video shows fast guys ending it, plenty to learn there
Select to expand quoteBSN101 said..
have a look at "WA finallly gets some wind" by Flex , video shows fast guys ending it, plenty to learn there
Even better have a look at this video courtesy Flex??How to speed sail choppy conditions, think Slowie hit 37knots 2sec??He would tell you it wasn't windy enough as well.
Those videos making it look easy.
A video of Phromsky's catapult described above would make me not want to try it. 40kts is nuts. I'm not sure if i'll ever be keen on that.
I only have freeride sails, can they sail deep enough?
I'm trying, i think i can get 25 with the Ezzy Cheetah 8.5 on the JP SLW one day soon but i think that will be it for my spot on this gear, 20ish kts max seabreeze flatwater 
Side question gps; I was using a Garmin forerunner watch when i used the board first time. Watch said i went 23.8kts peak speed, when i uploaded garmin gpx to KA72 it said i did 28kts peak. Is that a stitch up PB, anomaly or crash?
Lots of people talking about 'going deeper' here, and that is true, but only up to a point.
One of the first things we learnt in the early days of speed sailing at Sandy Point with those new-fangled GPS thingy's, was that in moderate to strong winds, (25-30 knots) we would go faster when we went a bit broader, even when it felt like the power in the sail and the pressure on the fin (back foot) was starting to decrease. But that is only to a point! In those wind strengths, that angle is around 120 to 130 deg off the wind.
But here is the thing: In lighter winds, that angle is less, and it can be greater in really strong winds. It's all about the apparent wind angle, not the true wind angle. If you go too deep in lighter winds, your apparent wind drops too much and you lose power. When you have enough wind to go well into the mid forties, you are usually really overpowered when running beam reach, with the combined true wind speed and high apparent wind., but as you bear away the apparent wind drops to the point where you can fully sheet in and be pretty much in control.
This is where flat water really helps (and I mean really flat water!!) And also a low drag board and fin! Really flat water gives you less drag and enables you to minimise the boards wetted area. It also allows you to use a smaller fin (less danger of spin out from shock loading over chop and the faster you go, the better it works) for less drag The faster you go in a given amount of true wind speed, the stronger and the further around in front of you the apparent wind gets, which makes it more efficient to go even broader from the true wind direction. This where efficiency, rather than brute power gets important. The myth that 'the bigger your sail, the faster you can go' is readily evident in really flat water. (not so much in rough or big chop where you have much more drag from the beard). What you really need is just enough power - the maximum your body weight and leverage can counter, and carrying more sail than you need just dramatically adds drag. The drag is from the excess sail area, but also from the weight of the rig causing more drag from the board on the water. And the faster you can go, the more apparent wind you have, the smaller sail, fin and board you can sail for the least drag.
So what all this means is that everything is a balance. The right amount of sail, board and fin size for the given conditions.
The deepest angles usually sailed on windsurfers is on the Luderitz speed channel. Depending on the wind direction, it can be up to 140 degrees off the wind. But to get down that course at that angle, you need an obscene amount of wind, and balls of steel because at that angle, with that much wind, even in the canal, there is going to be no flat water, and in fact it will be horrendous following chop. Antoine seems to cope with it by sailing inches from the edge of the canal where the chop is (for him) just survivable. Needless to say, there is zero margin for error, and almost everyone else at that time suddenly finds they have something very urgent and important to do elsewhere. Everyone else is looking for those magic moments when the wind is around 130 degrees (or a degree or two more) and the wind is minimum 35-40 knots. Thats when it is fastest for almost everyone else. Less than 30 knots and you are going to really struggle to even get down that course at all in 135 degrees off the wind. but add chop more than a few inches and that equation changes. In the typical summer SE steady 25 knots winds at LG, it is rarely efficient to go deeper than about 125 degrees. This goes up to closer to 130 degrees when you are lucky enough to get gusts to 30 knots or above. In steady 15 knots of winds there in absolute glass, it is quite common to go 30 knots, but the angle is more like 115 off the wind, maybe 120 at best, and you are very definitely close hauled at that speed!
A word of caution when trying to interpret the polar plots. You have no real way of knowing the real angle of the true wind at any one time. Those runs that appear to be over 130 degrees of the plotted average wind direction, could in reality, and most likely, have been during a variation or swing in the wind direction from the average, during that magic gust that produces your best ru.
The thread before last about the downwind faster than the wind vehicle there was also some talk of how deep is it possible to actually sail. On the foil it's possible to run very deep, not fast, but still faster than the wind. I contemplated that at times, it at least feels like you're running straight downwind. More time on the water and more contemplation leads me to believe that it is more the effect of catching a knocking gust that contributes to that sensation. Namely because it generally occurs on one gybe direction and not so much the other. I'm wondering if some of that is what goes on here.
Chris is an amazing sailor, and from what I've seen he generally sets a bigger sail than what others do. No doubt that helps him to bear off deeper as the apparent wind angle swings that bit more than others on a speed run, apparently very fast for him at least. Does it equate to that should be faster for everyone? I dunno. He also has a fair bit of weight on his side.
Phromsky's got it right. The leading edge shape must be flat and lean for upwind, but deep and curved for downwind. The reason the sail feel twitchy downwind is that the flat leading edge is generating turbulence vortices.
It's all about the direction of the apparent wind. Upwind the apparent wind is hitting the sail from the front. Downwind the apparent wind is hitting the sail from the side. (I made a two foot long stick from a piece of batten that attached it to the mast and stuck it out straight ahead. To the tip I attached a yarn telltale. Upwind the yarn pointed just a few degrees downwind of the sail. Downwind the yarn pointed nearly 70-90 degrees out to the side. Planing and fast both ways.)
This is exactly why they developed on the fly adjustable outhaul. More for leading edge shape than for draft. Formula racing elucidated this very clearly.
Today in a 15 to 20 knot breeze i was a few hundred metres behind and upwind of Slowboat on his 130 litre and new KA 7.7 and Jay on his Patrik 7.8 and 115 Patrik - i presume.
Two of the biggest, fastest sailors anywhere.
For a kilometer plus or so they were neck and neck until the sandbank stopped the drag.
Guessing across the wind they were both reaching 31 to 32 knots. Off the wind i am guessing they both reached peaks of 36 to 38.
Water state was a bit choppy for the river.
The National slalom champion of Korea who also sails at Melville is also really fast but perhaps half a knot slower.
I prefer to have my mast base as far back as possible to maximize lift and to be on the edge.
Lift the windward rail up to get the wind under the board and try to maintain the angle for as long as possible to maximize speed.
Was on my 5.6 but my 5.4 feels much nicer and lighter so going to ditch the 5.6 this summer.
Have a massive 6.3 Maui sail coming today for those light days.
this footage is basiclly beam reach to slightly off the wind, trying to pick a line through the chop. Trying to fly the board and keep windward rail up. Different video angle so hard to compare. But super enjoyable session.
Great thread, and it's usually a matter of bearing off more to get those top speeds when you're learning, or at least trying to slingshot off the wind in a gust!
Given all the polar plots, thought I'd check one of mine when sailing at Stanley in what was quite a broad run for that day. Heading into the bank and picking up speed requires a commitment to then bear-off or hit the bank!
Select to expand quoteAUS02 said..
it's usually a matter of bearing off more to get those top speeds when you're learning
The "when you're learning" is the key. If you're coming from "free riding", often better described as back-and-forth sailing, then going even just 10 or 15 degrees off the wind can feel very deep. I have see it many times where someone new to speed surfing was going 5 knots slower than someone with more experience on similar gear at the same spot. When you compare the angles and polar plots, it often shows that the faster sailor went 10, 20, or even 30 degrees deeper for his top speed. At the angle where the less experienced sailor got his top speed, the speed difference is a lot less.
That's just one aspect, and not the whole story. Skill and experience play a big role, too. A lot of "how to go fast" tutorials and videos focus on trim. I understood some of the theory behind that, but it really took a number of sessions in ideal conditions with a bunch of better sailors, lots of tips and explanations from better sailors, and some experimentation, to figure out what exactly I needed to do to get faster. Lots of those things were "common wisdom", but a one or two essential elements actually went against common wisdom, much to my surprise. I don't think I would have ever figured those out without the advice of someone who'd sailed 10+ knots faster than I had.
Nice session Dave. 
Looking at that polar diagram, it appears that the best top speeds are about 132 -140 off the wind.
I am a little surprised at the 140 angles, but they may well be a slight swing of the wind in the squalls. As I said before, I am not sure of the accuracy of that graph when the wind is always swinging though a range, sometimes 15-20 degrees, so the average shows a certain direction, but may not take into account the actual wind direction swings on individual runs.
I'd be interested in hearing Boardsurfr's comments on how that Polar Graph is programmed.
anyhow, to address the original statement.
Getting over 30 Knots really is not that hard if you have:
1. Flat water (so you can bear away at the best angle, in control and with minimal drag)
2. 20'ish+ knots of wind
3. A modern smaller to mid size slalom board and powered by a modern Freeride/Freerace/Slalom rig to suit for your size.
So I would say the obvious thing in this case is that you are missing one of those 3 things, and since 2 and 3 seem to be covered, it looks like you don't have flat enough water.
Here is a video from 2021 on really flat water at Lake George, South Australia. I averaged just over 30 knots for this Nautical Mile almost effortlessly, on an Isonic 80 (2017), Ka 5.7m Koncept/Speed sail, 20cm Atomic Nuclear weed delta fin. The wind was dead south average (183 degrees- confirmed on the Polar Plot). The measured angle from the GPS track is right around 115 degrees off the 'average' wind with only a few degrees variation either way at most. The wind in this run was no more than 20 -22 knots in the gusts, and mid to high teens in the Lulls. I have had considerable experience in this situation learning the optimum angle to sail, and this definitely was it. Any broader and I lost speed and pressure (confirmed in real time by my speed talk app), even in the slight gusts. Note that it was not very windy for this size gear. It took a while to get planing at the start. I am about 75Kg in my sailing gear. Most sailors this day were on larger gear. My second best peak 2 second speed of the session (33.85 Knots) was during this run. The max 2 sec for this session (34.2K) (Top center of the map) was on the other tack and was in a freak puff of maybe 25 knots, and probably in a wind shift, as it looks way too broad on the trackmap for this amount of wind strength.
The polar plot of max speeds for this session is very deceiving, and it suggests that those speeds were very broad, when in fact they were no more than 120 degrees off the wind. I think this is an artefact of the normal variation in wind direction of probably 10 to 15 degrees from average, especially in the gusts where max speeds are sought out, but I wonder if the plot is affected by the Gybes as well?
Here is the session track with the NM highlighted:
Video of this run with Telemetry (knots):
Select to expand quoteFlex2 said..
In addition to what Shifu mentioned, polar plots are sort of like your sailing signature. You can also read VMG (Velocity made good) or upwind/downwind speed directly from the plots. If you are in race conditions, sailors that can get upwind the fastest should have the most advantage, or in speed sailing you get back to the start quicker in order to have a chance to score more gusts. I also find it a useful way to compare fins (or any trim settings) objectively if you keep other variables the same. i.e. does fin A get you upwind faster than fin B but does it give you a speed penalty on the downwind run.
Here is an interesting comparison of 3 sailors at same location at same time. Cannonball is textbook sailor with peak speed around 36.4kts on both port and starboard tacks at nearly exactly 135 deg off the wind. Boz sails for speed only on the starboard tack but gets peak speeds around 41.4kts in a wider range 135-150deg off the wind. Slowboat sails only starboard speed runs but at ridiculously deep 165 deg off the wind to get peak speed around 47.9kts. Slowy is always banging on about having to go deeper to go faster but this is crazy deep.
Whilst both Boz and Cannonball have upwind VMG's around 12kts vs Slowy's 14kts, the downwind VMG's of Cannonballs 27-28kts vs Boz 35kts vs Slowy's 45kts show the massive difference in speed sailing ability of each sailor to ride big gusts.
dont throw slowy in to the equation
i dont think he is human
watching him sail in chop is awe inspiring.
I've never thought to look at the polar plots, so I went back and looked at a couple of pretty ordinary days at the end of last summer when I knew I did over 30 in the smooth. Both sessions I'm using a 95L speed board and Overdrive 6.2. The first pair below was about a 15 knot day. The second was maybe around 18 knots. Only two of us went out so it obviously wasn't a fantastic day (although if I recall the previous day was really good so maybe people were taking a rest). I tend to rig a little small because I feel like there is less drag if I can get going.
Anyway make of it what you will.
[EDIT: looks like I go a little over 150 degrees when its really good.]
That there just highlights the problem with those polar plots.
The first one looks about right where your fastest speeds are around 115 to 120 off the wind. Thats what I would expect in a=winds around 15 knots.
The second does not look right at all. There is no way your fastest speeds in 15 knots of wind will be even 130 degrees off the wind, let alone more and certainly not approaching 150. This plot just tells us you fastest runs were in gusts that had a quite large wind direction shift.
