Foil Tack Footwork

 Yesterday, a few videos came out that showed fully windfoil tacks that were fully foiled through - here is one of them: 

Sure, Balz Müller had shown fully foiled tacks a couple of years ago already, but his tacks were Duck Tacks. Duck Tacks may be "easy" for world class freestylers, but they out of reach for most regular windfoilers and windsurfers, and they are just about completely impossible with large race sails. 

In a regular windsurfing tack, you always loose just about all speed when tacking. In foiling, that's not the case - even mediocre amateurs like yours truly can keep a few knots of speed for the entire tack, and good racers keep so much speed that they pop right back up onto the foil. But compared to other foil disciplines, that's not really that good. America's Cup boats foil fully through their tacks all the time, often at speeds well above 30 knots. Advanced wingfoilers often foil through their tack; I recall a wingfoiler in Florida who would always jibe on one side, and tack on the other, without ever touching down.

But until yesterday, all windfoil tacks that I have seen had included at least a brief moment where the board touches the water. In my tacks, that usually happens when I put my front foot in front of the mast, or a moment later when I shift my weight from the back foot to the front foot. No surprise here - put your weight far forward, and the board goes down. So the critical question is: how can you get around the mast without putting your body weight in front of the mast? Just head over to Windsurfing.TV on Facebook and check the foil tack video there (https://fb.watch/cSdv0BHLkY/): it has a big smiley face that hides the foot placement.

So let's have a closer look at how the windfoiler in the video above solves the problem. Here is a screen shot as he carves into the tack:

It's a hard carve, but there's nothing unusual about it. That happens a little later:

Here, Harry started moving his front foot. Note that he has not moved the back foot, so it carries all his weight, which pushes the board higher out of the water. In a normal tack, we usually put down the foot in front of the mast, and then step forward with the back foot - but Harry does not stop moving his foot until it is on the other side of the mast:

With both feet behind the mast, his weight remains further backward. It also helps that the sail is tilted far towards the back, moving even more weight to the back. Let's look a fraction of a second later:

Harry is now moving his old back foot to the other side, again without putting it down in front of the mast. Note that the other foot has moved quite far back on the board already, again putting weight towards the back of the board. In the final picture of this series, he has both feet on the new side, and well behind the mast:

Clearly, the talented 15-year old Harry Joyner has figured out how to get around the front of the mast without ever putting his weight in front of the mast, which allows him to clearly foil through his tacks.

For a bit more detail, here are screen shots from a different perspective, taken from a video Harry posted on Instagram (https://www.instagram.com/p/CdOOkRzMA3f/):

Carving hard into the tack.

Two seconds later, still carving hard.

Just about to move the front foot.

The front foot is starting to move. All the weight is on the back foot.

The old front foot goes around the mast to the new side, without stopping in front of the mast. The front hand moves to the new side on the boom. Note that the board having all weight on the back foot has pushed the board higher out of the water. 

The foot does not stop moving, but right away slides further back on the new side.

The old back foot starts moving, with the old front foot already quite far back on the new side.

Harry keeps moving to the back of the board. The new front foot briefly touches the board behind the mast.

The new front foot keeps moving back, with all weight on the back foot.

All that weight on the back has kept the foil flying high.'

Ready to get going on the new tack.

It will be interesting to see how many racers will be foiling through their tacks this year. My bet is that many of the top guys will. In hind sight, it seems a bit surprising that it took several years of racing before someone figured to out how to foil through tacks. But maybe that's because all those windfoilers with a windsurfing background has the "step before the mast" too deeply engrained in their muscle memory.

Foil Jibes, Big Feet, and Forgetfulness

Back in February, I posted about a foil session where I had tons of good foil jibes, thanks to help from Andy Brandt. I should have known that would not last! After all, Andy also taught me how to plane through windsurf jibes ... and then, I had to take another dozen ABK camps where he had to jog my memory how to jibe properly. He was usually able to fix my problems within an hour. But in the weeks and months after a camp, I'd start forgetting, and went back to practicing bad old habits instead.

Windsurfers have to be optimists, so I hoped that this would not repeat itself with foil jibing. But whenever I tried to jibe back home on Cape Cod, a typical result would look like this:

Well, perhaps not always this flashy, but usually wet. Which is a real bummer, since I got that faster foil which really calls for using big cambered sails - sails that I really do not want to waterstart or uphaul all the time!

I was coming close to resigning myself to a lifetime of foil tacks when my endless hours browsing windsurf and windfoil forums paid off. A fellow foiler whom I had met in Corpus Christi posted a picture on Seabreeze that illustrated what had helped him to foil through jibes. The key was to have both feet pointing forward, towards the nose of the board. So a couple of foil sessions ago, when my initial foil attempts had resulted in the usual crashes, I tried his tip. Immediately, my jibes remained dry! They may still have been ugly as hell, with lots of wobbling, but at least I was not falling anymore!

A look at the GoPro footage from the session reveals that the differences in foot orientation were much smaller than I thought. Here's how my feet were placed in the initial crashed jibes:

Note that the back foot is almost perpendicular to the long axis of the board.

For comparison, here's a screen shot from a later (dry) jibe where I tried to have the toes pointing forward:

The difference in foot orientation is much smaller than I thought - maybe a 20 degree difference for both front and back foot. The feet are also closer together in the long direction of the board, as can be seen by looking at the distance from the front heel and the back toes to the black line on the board. This means that smaller steps are required during the foot change. Together, these changes made the "dry rate" in the jibes go from 20% to more than 80%. So far, so good!

Thursday was another great day to work on foil jibes at Kalmus. Just check out the wind graph:

Some Kalmus windsurfers may want to point out that northerly directions are not so great at Kalmus, and use the lulls of 5 mph and gusts up to 25 mph as "proof". But then, neither would they go out in the 10-13 mph averages that we had at the beginning of the session! But northerly wind directions are offshore at Kalmus, meaning the water is very flat. Just perfect for jibe practice! You don't need to be an expert to enjoy the conditions, either - Joanie, who is still a foil beginner, had some very nice long foil rides today with her 5.4 m sail. 

My only goal for today's session was to focus on the foot work in jibes - the initial setup with feet pointing forward, and a smooth(-ish) foot switch. I jibed 15 times in the 2 hour session today. 14 of those jibes were dry, which I am quite happy with. Some where nicer than others; today's GoPro footage was quite useful to get hints about what might cause the problems, and what to try to fix them.

In a few of the uglier jibes, the sail flip felt very unbalanced, and I often had to grab the mast instead of going boom-to-boom. Here's an example screen shot:

That sail has gotten away from me, forcing me to bend over. But why? A look at the board gives a hint: the leeside edge of the board is in the water. That means that the board is carving in the wrong direction! That's clearly visible in the GPS data for this jibe:

During the sail flip, the board turns back by about 15 degrees within one second. That does not really help to complete the jibe! But worse, it puts the sail in a pretty bad position - it's pretty much flagging out to the front of the board. No wonder something felt off!

To understand why this happened, we can look back a bit further in the video:

Check the placement of the old front foot as it is stepping back. The entire foot is on the wrong side of the center line - the lee side. As soon as I lift the old back foot to step forward, this will reverse the carving direction of the board! 

For comparison, here is the foot position at the same point in one of the better jibes of the day:

The new back foot stepped about a couple of inches closer to the old back foot, which makes it straddle the centerline of the board. With weight on the heel of the new back foot, the board will keep turning the right way even as I step forward with the old back foot. Indeed, the GPS tracks for this jibe show that the board kept carving about 10 degrees, from 148 degrees to the wind to 138 degrees. That's 25 degrees better, just because the foot placement is a couple of inches different! With the board continuing to turn the right way, the sail flip on this jibe was easy:

Maybe the jibe was not perfect, but I was able to keep the speed above 7 knots, which let me get right back onto the foil after the sail flip - good enough for me!

So the question arises: how can I make sure that the front foot steps back to exactly the right place? One possible solution would be to put the older carving foot further to the outside of the board, so that there is more space for that big front foot as it steps back. But when I tried this in the past, a new problem occurred: when lifting the old front foot to step back, the board tilted a lot, which often resulted in a crash. That sometimes made for great screen shots, where it look like I'm trying rail rides with a foil - but it did not make for dry jibes. In other tries, I would feel the board starting to tilt when the old front foot started to move, and I'd cut the step short to prevent the board from tilting. That, however, would leave it on the wrong side of the board again! So while the tip to "move the carving foot all the way to the outside" may work for some foilers, it does not work for me.

But let's have another look at the last picture above, where the sail flip worked well enough. You can see that both of my feet are in front of the foot pads - in other words, too far forward. That means that the board will go down and touch the water, and won't start flying again until I moved both feet back again. For the goal of fully foiled jibes without water contact, that's not good enough. It is, however, very typical for my "good" jibes: even in my session in Corpus Christi, where I almost foiled cleanly through many jibes, the board would often touch touch briefly just after the sail flip (or, in sail first jibes, the foot switch).

So I really have two problems, let's call them "wrong side" and "too far forward". My lovely wife never experienced these problems, and I think that's simply because her feet are a lot smaller, so it's much easier to find space on the board. Unfortunately, blaming my big feet does not really help. What might help, however, is stepping heel-to-heel, making sure I feel the foot that moves back actually touch the heel of the old back foot. That would place the back foot a bit further back, and the heel on the correct (windward) side of the centerline. If we now assume a constant size for the step forward, the front foot should also end up a bit further back. That would be progress.

But one of the things that I glossed over somewhat was that in the initial setup, I move the feet closer to each other in relation to the long axis of the board: the back foot goes forward a bit, and the front foot goes back a bit. That allows for smaller front-to-back steps during the foot switch, which in turn leads to a steadier flight. To "undo" this, it may be necessary to modify the foot placement during the switch: the old front foot steps behind the old back foot (but still heel to heel). That should make it easier to keep the old back foot from stepping too far forward, and it also should give the foil a little push up to get flying again, or to keep flying. I can't wait to get back onto the water to try!

Foil Jibe Tips

 After a year of foiling, I still struggle with the jibes. The goal of foiling through jibes on a regular basis remains elusive. Of course, I have all kinds of great excuses. My foil board is narrow - only 22 inches (56 cm) wide. Just about every article about foil gear in the German "Surf" magazine states that wider boards are easier to jibe when foiling. But this excuse seems a bit lame when I look at my lovely wife, who foiled through jibes on a regular basis .. on her skinny 90 l freestyle board. So I won't even bore you with my other excuses, which are even lamer.

Instead, I'll share a few insights I had after watching a couple of jibe tutorial videos from Sam Ross. Here's the step jibe tutorial:

The jibe is quite similar to a jibe on slalom gear. One of the differences is that he sails clew first briefly after stepping to stabilize; that's quite common for foil jibes even among racers, but unusual on slalom gear.

Overall, Sam's technique is very similar to what Nico Prien shows in his jibe tutorial video. One thing that looked very familiar in Nico's video was the "oversteering" mistake he shows at 5:44 in the video:

This has happened in many of my jibe tries: the board just keeps carving, and the foil seems to be pushing the board into an even harder carve when the windward rail catches the water. Nico points out that "you need to actively balance the bank" - in other words, flatten out the board to stop the turn.

I started trying step jibes on the foil, but moving the feet and the rig at the same time while the board is in the air always seemed a bit too much for me. Largely based on Andy Brandt's suggestion at the ABK camp in Hyannis last year, I switched to sail-first jibes instead, where you sail out in switch stance and move the feet later. I have no problems with sail-first jibes on windsurfing gear, but on the foil, they seemed just as difficult as step jibes. So maybe the tutorial video from Sam Ross, who calls it the "strap to strap gybe", would help:

Comparing the two Sam Ross jibe videos, there's one big difference I noticed: the position of the mast during the sail flip. In the step jibe, the mast is moved to the outside of the turn:

That's the same when windsurfing. But in the sail-first foil jibe, the mast does not move to the outside - it stays perpendicular to the board:

Since the board is banking into the turn, the mast is also leaning into the turn a bit. When teaching the jibe at the ABK camp last year, Andy Brandt said we should keep the mast to the inside of the turn. I guess this is what he meant! I over-interpreted his instructions, and thought that the mast should point even further to the water - something that's hard to do if you are not oversheeting.

Interestingly, during the sail-first jibe when windsurfing, moving the mast to the outside of the turn is not a problem at all. But the foil is much more sensitive, and moving the mast to the outside when letting go with the back hand immediately changes the carve, and makes it nearly impossible to complete the jibe dry.

When thinking about the instruction videos, I was wondering why foil racers always seem to step jibe, while many early foil jibe instruction videos used the sail-first jibe instead. Both Sam's and Nico's tutorials provide a clue when they talk about slicing the mast forward: on race foils, foilers are often going faster than the wind. That makes opening up the sail impossible, since you'd just get backwinded. On the foil, that means that the foil would probably shoot up and out of the water for a spectacular crash.

The sail-first jibe requires that you are going slower than the wind, since the wind pressure from behind flips the sail. In contrast, a step jibe also works when the apparent wind is coming from the front because you are faster than the wind; you just have to make the sail flip similar to the sail flip in a helicopter tack.

Both Nico Prien and Sam Ross are on race or freerace-type foils and boards. In Sam's "How to go Faster on the Windfoil" tutorial, he reaches speeds of 26 knots. But typical speeds on freeride foils like the Slingshot Infinity 76 or 84 are much slower. My typical cruising speeds on the i84 are around 10-12 knots, so I'm going slower than the wind speed most of the time. That makes the sail-first jibe possible, and it has one big advantage for "marginally coordinated" foilers like me: I can concentrate on one thing at a time, and don't have to move the sail at the same time as I move my feet. Time to go foiling!

Tracks for the Skate

After discovering that simply replacing a powerbox with a foilbox did not work well for my Skate 110 and Slingshot Inifity 84 foil, I decided to put a couple of US fin boxes in the board so that I could use the pedestal mount for the foil. The big advantage of the track mount is that it gives a few inches of room for adjustments so the foil can be place at just the right spot. Here's a picture of the finished installation:

We got a bit of wind today, so I took the combo out for a test run with the i84 foil, the 71 cm mast, and my 6.5 m Gaastra Matrix sail. The session was a bit frustrating because the chop was quite high even though the wind was light - too light to waterstart most of the time. I also had to get used to the foot straps on the board (I don't use any on the 71 cm wide slalom board I usually foil on), and had a hard time with tacking - after sailing a lot on the wider slalom board, I often stepped too far to the outside or even next to the board. Bad turns and uphauling in chop - not my favorite combo!

But the good news was that moving the foil forward worked as expected, and so did the track mount. I had the mast in "C" position on the fuselage, and pushed the pedestal all the way to the back. Here's a video from one of the longer runs:
I had put a Slingshot half footstrap in the back, since installing the foil box had removed the rear screw holes in the center. It actually was too far back for the foil position, so I ended up not using it. I'll either turn it around and mount it as far back as possible, and/or I'll have to mount the foil in "B" position on the fuselage. That would move it a couple of inches further back, but the track mount makes it easy to fine tune the position.

There were plenty of crashes in this session. Here's one where it looks like I'm going for a Gecko:

That would be a rather questionable idea without using the rear strap .. and with the foil behind me to fall onto! Maybe all the water that seems to be coming out of my head in the next picture can be blamed :-).

Squiggles and Half Straps

Yesterday was supposed to be good for foiling in the afternoon, with wind in the mid-teens. We waited for it. And waited. And waited some more. It was almost 5 pm before the meter readings picked up to 13. 45 minutes later, I was on the water at Kalmus. Nina decided not to join me after hearing about jellyfish on shore (a first for this year), and seeing rain showers coming in.

I had rigged the 6.5, which proved plenty big when the wind picked up to 16 mph averages. Since the tide was high, I was able to use the 90 cm mast, which is easier and more fun than the shorter masts. On the back of my zombie slalom board, I had mounted one of the Slingshot "half" footstraps, with the open end facing forward, to test it.

Here are the GPS tracks from the session:

It was a great session! Due to all the jellyfish talk, I skipped working on jibes and just tacked, with 11 of 14 tacks dry. I also crashed once in the middle of a run. The swell was quite big for the light wind, with some 2-foot rollers coming through from time to time. My Infinity 84 foil is quite sensitive to what happens in the water, and going almost parallel to the waves means that the flight height can change quite a bit going up or down a wave. So after a while, I gave up trying to foil in a straight line, and instead played with the swell. When going down a wave, the foil wanted to go drop down to the water; when going up the back of a wave, it wanted to rise up. Once I figured that out, compensating for it by moving the rig or my weight was a fun little exercise. The long mast definitely helped there! Breaches were virtually non-existent, and touch downs were gentle and brief. Drawing squiggly lines in non-breaking wind swell is so much fun!

I liked the half strap in the back. It is quite easy to slip into it sideways, and having the strap helps to have the foot in the right position, and perhaps a bit more control of the board. On the side without the strap, I found myself looking down a lot to see where exactly my foot was. I guess I'll put the second strap on the other side, but leave the front straps off for now.

I kept the session short since it looked like more rain was coming, and I did not want to make Nina wait too long. But doing a short foil session meant that I never reached the point where my attention starts to wander, and crashes slip in. We ended the day by celebrating the end of the tourist season at the British Beer Company. What a great start of September, my favorite windsurfing month of the year!

Foil Setup: Front Wing Placement

Isn't it curious how sometimes things can be easy and confusing at the same time? Setting up equipment for windfoiling can be that way. The general rule is simple: "you want the front wing located as close to the center of your stance as possible", the Slingshot manual says. Sound easy, right? Let's look at a few examples, starting with Nina's foil setup:

This is her old Skate 90 freestyle board and the Slingshot Infinity 76 foil with a 60 cm mast, the gear she uses for foiling 90% of the time. She can foil on this in 12-13 mph wind with a 5.2 m freestyle sail, with very good control. She's also foiled through a few jibes, and started on duck jibes and 360s. Let's zoom in a bit:

I placed the ruler close to the middle of the front wing, where the "center of lift" (COL) is. If you compare it to the position of the foot straps, you can see that it is close to the middle, just a bit towards the back strap.

Now lets look at another setup that does not work nearly as well:

This is my Skate 110 with the Slingshot Infinity 84 front wing. It's shown with a 45 cm mast, but ignore the mast size for the time being. Here's a zoom-in:

You can see that the COL is much closer to the back strap. When I tried this setup (with a 71 cm mast), it was hard to get up on the foil, and felt very unbalanced once up. Nina tried it, too, and came to the same conclusion.

What's the difference? In both setups, the foil is mounted in the "C" position on the fuselage, which put the front wing closest to the front. However, my Infinity 84 wing is significantly larger than Nina's i76. All the extra area was added to the back of the foil, which moved the "center of lift" back by about an inch or two. In addition, Nina is using the Powerplate to move her foil forward even more:

You can see that the Powerplate here moves the mast forward by about 2 inches. In total, the COL for Nina's setup is about 3-4 inches further forward than for my setup!

So the obvious thing to try is to move the front wing for my setup further forward. I did this by drilling a new hole into the fuselage exactly 2 inches behind the rear hole for the "C" position. By using these two holes, I now have a "D" position where the front wing is moved forward two more inches:

You can see that the COL has moved forward to be closer to the middle of the foot straps. When I tried this setup, it worked a lot better. The foil came up a lot earlier, and it felt more balanced when up. But please note that the extra hole weakens the fuselage, and that the larger distance makes it more likely that the fuselage will bent! So I'm not recommending that you copy this approach!

When I replaced the powerbox in my Skate with a foil box, I put the foil box at the same position that the powerbox had been in. I actually had tried to use the Skate 110 for foiling before, and it had worked well enough - but I completely forgot that I had used the Powerplate, which moved the foil forward! In hind sight, I should have just added a couple of US fin boxes to the Skate 110 for use with the Slingshot pedestal mount. Adding the tracks so that they partially overlapped the powerbox would have been easier than using the foil box, and given me some adjustment room (in addition to the option to mount the mast in the A or B position). That would have made it easy to fine-tune everything for a perfectly balanced setup.

One thing that perhaps let to my confusion about the box placement is that the "C" position works very well with my slalom board:

I don't use foot straps on this board for foiling, so I placed booties where I usually put my feet. The back foot is usually all the way back against the strap that I use to attach a safety line to, and the front foot placement varies a bit depending on conditions and power. But it is easy to see that the distance between COL and back foot is more similar to Nina's setup than to my "unbalanced" setup shown in the second picture.

A closer look at the footstrap placement on the different boards reveals a significant difference: on the slalom board, the back strap positions are about 2 inches further back than on the freestyle board. That's true for the boards shown, but also for several other (newer) Fanatic slalom and freestyle boards in the garage. On some foil boards like the Slingshot Wizard, the back straps seem to be even further back, so that the back foot is where the mast is. Here's an image of the Slingshot Wizard 125 with the foot strap position highlighted:

For comparison, here's an image of a typical freeride board:

The back footstraps are several inches forward of the fin / foil box, similar to what we saw for the Fanatic Skates.

So, if you'd want to use a Slingshot Infinity 76 foil with a Wizard 125, the consensus is that the mast should be in "B" position on the fuselage. For use with a typical freeride board where the footstraps are further forward, the mast has to be in "C" position for the i76.

For the Slingshot Infinity 84 front wing used with a Wizard, the foil should be mounted in the "C" position. This means that use with a freeride board would require a "D" position! Since the fuselage does not have a "D" position, anyone trying such a setup will likely be disappointed (or has drill an extra hole).

Interestingly, Fanatic has chosen a more forward footstrap position for their foil freeride board, the Stingray:

There are lots of option to mount the rear straps, but all of them are pretty far forward. This makes sense, since Fanatic also sells several "foil ready" boards with similar strap positions. All these boards need to work well with the Fanatic foils. Compared to the Slingshot foils, the Fanatic foils have the front wing mounted further forward (the mast is further away from the front wing), which is necessary for a balanced setup.

If you buy a matching foil and foilboard from the same brand, this is not an issue, since you should be able to simply follow their setup instructions. But it you try to "mix and match" foils and boards, subtle differences like a 2-inch variation in the footstrap placement can make the difference between a setup that works beautifully and a setup that is barely useable. Similar issues arise from the position of the foil on the fuselage. For example, RRD freeride foils have the mast mounted close to the middle of the fuselage, while the Slingshot Infinity foils have the mast closer to the front wing, even in "C" position.

For board conversions, some of these problems should be avoidable by going the mast track/pedestal mount route, especially for Slingshot Infinity foils. Whatever option you choose, though, I suggest to check where the front wing will end up before you start the router!
--
I have contacted Slingshot with a suggestion to add a "D" position to the fuselage, and heard back from Wyatt Miller, their windsurfing guru. He said moving the mast further to the center increases the chances that the fuselage would bent, since it has more leverage. Nor does it help that the extra hole weakens the fuselage! Apparently, jumping with the larger front wings (Infinity 84 and 76) can bend the fuselage even in B or C position, so Slingshots suggests to use smaller front wings for jumping and things like loops. I had actually noticed a bit of new instability when using the "D" position, but the i84 is always sensitive to water movement caused by chop and swell, so it's hard to tell if this was caused by increasing the distance between wing and mast. To be on the safe side, I'll add a track mount to my Skate.

Foil Box Conversion

With the ABK camp in Hyannis coming up in 4 weeks, it was time to get my board ready. I have been foiling on my old Warp 71 slalom board without footstraps, but that just won't do when we start working on foiling 360s. So out with the powerbox, in with the foil box! 

We had used the Skate 110 a few times with the Powerplate to see if it would work (it did). When I put it up to start on the fin box replacement, I noticed that the Powerplate had damaged the underside of the board:

Where the front end of the Powerplate meets the board, the top carbon layer was broken.  No big deal to repair, but it sure was good I had ordered a foil box!

I studied a couple of videos from Alex Aguera to get an idea on how to do this. I ended up buying a router at Harbor Freight Tools, and used it to get the old powerbox out. Here's an image from the start of this process:

I had never used a router before, but it went well enough. Cool to learn how to play with new tools!

Fitting the new box was not hard. I hit the first surprise when I glued it in with epoxy and fairing filler: when turning my back for a minute, the box started to drop, and was half way through the board before I noticed! Luckily, I turned in time, pushed it back up, and added some support below to keep it from falling again. Here's the setup:

The masking tape on the sides is keeping the fin vertical to the board. After a bit of sanding next day, the box was ready to be glassed in:

I used a layer of carbon and two layers of 4 oz S-glass, topped by a layer of 2-oz glass, on the bottom:

This was the first time I used 2 oz glass on top. This stuff is great! It makes a much smoother surface, and does not distort when you squeegee the epoxy. 

Everything had gone well so far, so I pushed on. A few hours later, I glassed the top side: a layer of 4 oz glass, 5 smaller pieces in the middle, and another layer of 4 oz and 2 oz. I copied Alex' approach, and put all pieces on before putting the epoxy on top and massaging it in. Worked great, and another new thing learned. But then I saw that the glass in the middle was bulging outward .. not good! But a few more minutes with the squeegee, and the extra air was pushed out. I watched it for a while, and then let it sit for a few hours to polymerize.

When I got back, there was an unpleasant surprise: the bubble had reformed, and pulled the glass away from parts of the fin box. Apparently, glassing both sides of the box was a bad idea. A slight increase of the outside temperature made the air expand. Usually, I glass in the late afternoon, when temps are dropping, but today, I had clearly started too early.

Fixing the problem required drilling a few small holes, injecting epoxy, and then pushing the center of the glass down. The setup included some wire, three pieces of wood, and a 12-lb weight, but it did the trick. First, though, I put a few small holes in the bottom where the glass covered the fin box, so the air could escape!

The next step was removing the glass cover at the bottom with the router and a trim bit. That was really quick and easy - cool! All that remains to be done now is finishing work - sanding, drilling a couple of holes for the screws, hot coat, and paint. The board should be ready for foiling in a couple of days, which should mean that we get plenty of wind at the start of the week to keep me on the "slapper". There are worse fates!

Jibe Practice for Foiling

We got our second foil three days ago: a Slingshot Infinity 84. I've foiled on it only for two short sessions, but so far, I love it. It gets me flying as quickly as Nina on the Infinity 76, with a sail that's just one sail size bigger. But more importantly, it can handle all my extra pounds much better than the 76 - no more spinouts and breaches! But my first attempts at foiled jibes on the i84 looked quite similar to those on the i76 - mostly crashes, with an occasional exception where I plane out of the jibe after the board touches down.

As new foilers, we are in a stage where we often hope that the wind does not pick up beyond 15-18 mph. This summer so far, the wind often has played along, but not yesterday - it picked up to the high 20s, gusting to 30. So it was time to take the old slapper out for a change - my white Skate 110 that I had repaired for foiling, since I had forgotten to put my new Skate into the van. Off to Egg Island we went. Nina tried her usual freestyle moves, but I was on a foil related mission: practice the sail first jibe!

After more than 20 AKB camps, I am a step jiber - when the sail moves, the feet switch (or at least they should). But for foiling jibes, there's plenty of advice to do a sail-first jibe (also called Power Jibe and Speed Jibe): flip the sail first, and the feet later. That's what the Horue jibing tutorial suggests, and Balz Muller says the same thing. I have tried enough step jibes on the foil to see that separating the sail and foot movements might be a good idea, but I almost never do sail-first jibes .. which means I did not really want to try them when flying. But being nicely powered on a 5.0 on perfectly flat water at Egg Island - there's no better training grounds!

So after a few regular jibes and a 360 try or two, it was sail-first jibe practice. I was surprised to find me planing out of them after just a few tries, and having tons of fun! I'm not good at multi-tasking, so flipping the sail first while maintaining the carve, and then switching the feet, seemed more natural to me than doing two things at once. When the wind picked up after a while, I ended up doing tacks on one side so that I'd be able to do some "slow speed runs" along the sandbank on the way back. Since I tack the foil much more than I usually tack my shortboards, my tacks had improved a bit - nice!

Here's the GPS tracks from the "forbidden jibe" session in the "kiddie pool" at Egg Island:

The jibe analysis with GPS Action Replay showed that this was one of my top-15 best jibing sessions (from more than 1300 sessions). Cool!

Hopefully, the wind will remain lighter today, so that I'll get a chance to try foiling sail-first jibes. For anyone who wants to foil at Kalmus, check these tracks from my last foil session there:

I was using a relatively short (71 cm) mast, but still ran aground about 800 feet from shore at low tide (0.2 ft). I tried walking into deeper water several times, but always made ground contact again when I tried to foil away. You can see the stones pretty well on the Google Earth image. I would have probably been fine another 100 or 200 feet further out, but the ground there is uneven, and my head was barely above water in the deeper spots. I ended up just body-dragging in.
So if you foil at Kalmus, check the tides, and make sure to walk out far enough at low tide! Once the tide level goes beyond 1-1.5 ft, even a 90 cm mast should be fine, though.

Foil pictures

We had another nice foil session 2 days ago, and Eddie took some nice pictures. Here's Nina on the foil and Gonzalo on a longboard:

Nina was on a 5.2, Gonzalo on a race sail (8.5 or 9.5). He was one of the few windsurfers who was planing consistently - most guys on 7 m sails had a few good runs, but mostly slogged.

Fortunately for me, Nina was a bit overpowered on the 5.2, so she came in after a short session and let me have a turn. I started out on the 6.5:

I never like this sail very much, largely because it is low-end oriented, while all my older Gaastra Matrix sails were top-end oriented. However, it was great for foiling, powerful but stable. Cool!

The picture above shows my favorite "flight height" on the 60 cm mast: just barely above the water, so that the board just touches the waves a bit every now and then. One excuse for flying low is that I frequently get spinouts when most of the foil is out of the water. Those are usually not very dramatic, but often end up with the board slapping back down onto the water. The gently touches when flying low are much nicer, and loose a lot less speed. But perhaps it's really just my inner chicken asserting itself.

We took turns on the foil a couple of times, and I used the 5.2 for my second session. Here's another "flying low" picture:

Occasionally, I ended up foiling a bit higher, and I'm definitely making progress controlling the height.

I'm still amazed how much fun foiling is even at low speeds. My speeds typically were around 10-13 knots, with only rare spikes above 15 knots. That's about half of the speed of sailing on freeride or slalom gear! Here are the tracks for the day:

I had a few runs of 700-800 meters, pretty much the entire distance I foiled (limited by shallows on the left, and the stones from the old pier on the right). The longest "high foil" without touching the water was probably less than half of that distance. I made a few dry jibes, one of them close to planing, but did not foil through any. In contrast, Nina foiled through one of her jibes "by accident". I'm sure she'll have more of these "accidental foiled jibes" soon.

We have ordered a second foil, and it should arrive early next week. Maybe that will cause the strong summer winds to come back? We stayed with Slingshot because we really like the modular system, and the short 60 cm masts are great for low tide foiling. But we decided to get an Infinity 84 as the second foil (together with last year's front wing which Slingshot pretty much gives away for free), since I hope that it will push my almost 200 pounds up sooner. It may be a bit slower, but I don't think that's a bad thing anymore!

I almost ended up buying a Starboard GT-R foil. It would have been a few hundred dollars cheaper, and comes with a longer fuselage, which should make keeping a constant height much easier. One of the speedsurfers we met in Western Australia, Stroppo, regularly posts sessions with top speeds in the mid-20 knot range from the Starboard GT foil. Without any doubt, I'd be at least 5 knots slower (just like on the windsurf board), but that would still be plenty fast. However, I did not see any option to buy a shorter mast for the Starboard foil, which would have made foiling at Kalmus during low tide questionable, and foiling in the Hatteras sound impossible. So all I could do to imitate Stroppo was to try to look a bit like him:

During the session, wind averages from the iWindsurf meter at Kalmus were mostly 15 mph, with a few readings of 17; gusts were mostly in the 17-18 mph range, with a couple of 20 mph readings. I tried to plane with the 6.5 m sail on my Skate 110 a few times, but either the wind was too light, or I have forgotten how to sail a "slapper" in marginal conditions. When foiling, the 5.2 m sail was mostly ok, and only a bit smaller than I like in the lulls; the 6.5 was plenty big, and I could get up onto the foil pretty much anytime I liked, with (at most) minimal pumping. After 12 sessions on our foil, and about 20 foil sessions in total, foiling already had dropped the "good day" wind definition from 18-20 mph to 15 mph (and probably 13-15 mph). Sure, I could have planed with a 7.8 m sail on the 70 cm slalom board, but that would have been a lot more exercise and a lot less pure fun :-).