2019 Caribbean Laser Midwinters Championships Final Day

It was a brilliant last day of racing yesterday at the Caribbean Laser Midwinters Championships in Cabarete, Dominican Republic.  

I’m having trouble formatting and posting pictures from my phone so please check out my Instagram feed BowOutSailing for pictures of the sailing venue and scoreboard (I didn’t take my phone out on the water for action shots!). I have also posted some pictures on my Facebook page.

First place in both fleets was decided in the last race on a tie breaker with Sweden’s Jasper Stalheim 🇸🇪 coming from behind to win the double tie breaker against Norway’s Hermann Tomasgaard 🇳🇴.  There was a lot more drama in the Radial fleet that I don’t know first hand but young Dominican Republic sailor Perez Esneiry 🇩🇴 beat some stiff competition to emerge victorious - hopefully we’ll be seeing more of him.  

Back in the full rig fleet Elliott Hansen couldn’t quite edge out Lorenzo Brando in an all British National Team 🇬🇧 tie breaker for 4th.  But what happened to two time world champion Nick Thompson?  I heard second hand that he had an upper body injury and left the Dominican on the second day of the competition.  I hope he is okay.  

A bit further back in the fleet it came down to the last race between Canada’s John Owen and Dominican Republic Olympian Raoul Aguayo tied for 7th place and Ian Elliott (myself) and Ari Barshi tied for 9th Place.  Ari and I had been tied going into the day and I had won the first race of the day by one spot and he had won the second by one place.  In that race I had had a nice lead but failing to learn from Fillah’s mistake at US Nationals, I had allowed him to separate towards what I thought was the unfavourable side near the top mark.  His shift however came in and he caught right back up and passed me.  So now it was all coming down to the last race.  On the first downwind Ari and I were neck and neck with the lead potentially changing at every big wave 🌊 and at the leeward mark Ari and I were within a boatlength.  On the upwind I had a loose cover on him but then I sailed into a juicy knock with pressure that Ari didn’t seem to be sharing.

Segue...

On Saturday the regatta’s sailors were treated to a debrief by British Laser National Team Coach Chris Gowers, coach of reasonably good sailors Sir Ben Ainsley🥇, Paul Goodison🏆, Nick Thompson🏅.  Anyway he had an interesting point that in very strong fleets where everyone is doing most everything right (my part of this the fleet may not quite have met this standard) it comes down to who can figure out or intuit when to break the classic rules and truisms of sailings.  So I’d like to couch my next decision in the veneer excellence by invoking Chris Gowers...

Once again I decided to split with Ari and not learn from Fillah and not ‘stay between your competition and the mark’.

This time it worked and I gained enough that even with Ari’s consistent edge in downwind speed, he couldn’t close the gap and so I came out ahead in the regatta.

The last downwind was also exciting because John and Raoul had rounded the last windward mark close together and close in front of me so I could see it play out.  In spite of Raoul’s excellent downwind speed John momentarily passed him and it was looking like John Owen and Ian Elliott were both going to win our battles in the final race but Raoul’s veteran skill in the Cabarete swell pulled through again and he passed John again at the last minute before he final turning mark and they screamed in to the finish together on the final hot reach with Raoul edging John out.

New(ish) Gear

Most of my blog entries originate as emails that took a lot of time or effort to write that I think other people might also appreciate.  This one was going out to a list of Laser sailors who have been coming out for casual training on Sundays in Victoria this winter.  Other than John, I think I am the only one with a Mark II sail and carbon top section, so I thought I would give them a review in case they were thinking of new gear for Christmas, especially because Fillah Karim, a local West Vancouver Canadian Olympic hopeful is selling off a bunch of lightly used Mk II sails.

I don’t think anyone sells Mark One (Mk I) (classic style) fullrig sails anymore so the change IS coming/has come (although I do still have one lightly used Mk I if someone doesn’t like he new design).  Comparing Mark Two (Mk II) to the old sails: the fabric is heavier and the clew is much reenforced, which goes a long way to making the sail last longer - not amazingly longer but significantly longer.  The window is much bigger and the panels are now cut radially.  In terms of rigging, the only difference is that you may need an extra cunningham purchase because the heavier fabric and reenforced clew takes more tension for a similar depowering change in sail shape.  Bob thinks the cut gives MK II more power.  I’m not sure, could be.  The feel and shape of Mark II is significantly different.  Until you get used to it, it is not faster, it feels and looks weird, but once you dial it in, it might be a bit faster than the Mk I.  The down sides are: they use different (tapered) battens of three different lengths which is an unnecessary expense and so far I don’t think you can buy individual battens when you lose one.  Tapered battens in general are a cool high performance trick but the premise of the sail was that it would not be faster than the Mk I, so why?... At least the batten pockets are improved with high quality Velcro.  I thought this would make batten tension come into play, but so far we think that loose batten tension is best.  Another slight downside is that the luff of the sail looks very bad on the downwind.  I think you just have to forget about it and focus on your leech tension which is much more important downwind by the lee.  Also the Mk II is more sensitive to a bent mast on the upwind.  If you have a normal aluminum mast (as opposed to the new carbon one) for the best performance you need to straighten your aluminum mast whenever it gets a slight bend.  Also if the bottom caps fit loosely in the bottom section it is a bit more important to tape them snug than it was win the Mk I.  The consequence of not straightening or taping your top section with the Mark II sail is that it makes an ugly crease in the sail, though it isn’t really that much slower, it just looks bad.  In heavy wind some people actually try to create this crease to dramatically open the leach.  Crease or no crease, the difference between a Mk II, a Mk I or a Mk I intensity sail are smaller than the difference between a new and an old sail.  On the topic of Intensity sails, beware of Mark II Intensity sails.  They may be fine and my sample of 1 may just have been a lemon on a bent mast, but last year Rob Douglas up in Comox bought a Mk II Intensity sail and the crease was very bad in all conditions and we couldn’t get rid of it without stretching the sail much more than you wanted to for speed.  It was so bad that it was discouraging, so a used class legal Mk II sail may be the way to go on a budget unless other people know of good Mk II knockoffs.

Having mentioned the carbon top section, I might as well throw in my two cents about that too.  The Laser Carbon top sections are nice because they never get even a slight permanent bend in them so they mesh nicely with the Mark II sails.  They are NOT lighter than the aluminum masts which is hilarious, but they wanted it not to be an advantage which makes sense from a Laser point of view.  The only other difference is that hey feel a bit springier which might be an advantage in kinetics or wavy conditions.  The biggest difference in my opinion is that if it was very windy and then the wind died off, people with aluminum sections would all have a slight bend but the carbon ones pop straight as soon as you release the Cunningham and vang.  The biggest downside is that they are super expensive for what they are: a simple tube with the same old fittings.  Other downsides: they are more delicate because carbon doesn’t like impacts, though mine has stood up well for a few years now.  Also Laser made the carbon top sections exactly the same way as the aluminum ones riveting into them with aluminum rivets.  In the first generation masts there was only one rivet in the top section bottom cap and sailing put too much stress on that rivet and it has damaged the carbon. I tried to epoxy it back in place but it as cracked loose again.  Apparently they now sell carbon top sections with two rivets in the bottom cap and it looks like they may have improved the finish on the carbon at the bottom of the mast, so that problem may be fixed, but the fact remains that aluminum rivets in carbon might not last as long and stay as tight as they did in the aluminum ones.  So far (years) no problem with the rivets in the carbon top section collar... we will see.

So for the carbon section I don’t recommend buying one if you are on a budget unless you are heavy for the boat like me.  I was tired of straightening my aluminum top section after every session in over 13 knots and wondering when it will eventually snap and when I should end to end it.  Now I don’t have to worry about the aluminum fatiguing from all the bending and straightening at its critical point.  If you are a big sailor who bends their mast, the carbon section is great.  It is also worthwhile if you are campaigning and you want every possible advantage like springiness in choppy conditions.

In this strange new world where the second best, most accessible big-fleet racing boat in the world has it’s olympic status under review (Opti would be the best, Laser and Radial would be the second best) I wanted to give the new equipment a tardy but fair review.  I’m happy with both my new (ish) sail and new top section and I am planning on bringing my newly legal digital compass into play in the new year!

I’m looking forward to the new rudders coming soon which are supposed to be more balanced but I really want a carbon bottom section because I tend to bend that too in medium and heavy wind, but that is just me.  Very few other people seem to suffer from perpetually bent bottom sections...

Happy sailing or dreaming of sailing this winter.

This is more footage from Steve McBride when he was coaching us leading up to 2017 Laser Midwinters East in Clearwater.

This one is about fore-aft mobility for weight placement while surfing waves.  I really value the knees-up, weight-on-your-feet technique, and this is why...

Moving aft picks the bow out of the water when you have power in the rig.  Also I was finding that shifting my weight aft was helping my turns, preventing my bow from catching so much.

This footage comes from Steve McBride who coached a bunch of us in Clearwater leading up to 2017 Laser Midwinters East.

I call this skill pivoting: look at the cascade effect as it travels up the fleet. The 5th boat from the right pivots up into the wind to try to salvage their hole, then the 4th boat does (me) then the 3rd, then the second. If you don't know how to do it, you lose your lane!

Wind Accross Current

In an instructor clinic last year, Steve McBride and I were explaining how current affects the ripples on the water and so we naturally transitioned into the affect of current wind on apparent wind.  We talked about wind against current and wind with current and started to move on.  Naturally Abby asked what happens to the wind and waves if there is cross current.  Since we didn't want to get into trigonometry, we parked that question, but we never ended up getting back to it.  So at long last here is my answer, although as usual with this blog I got carried away with it...

Wind With Current

Starting from square one, If you are standing still on a moving walkway at the airport inside where there is no true wind, you still feel air hitting your face because the moving walkway is pulling you into the still air.  Relative to you there is what we could call 'walkway wind'.  This walkway wind comes in the opposite direction as your motion.  Current can be thought of as a moving walk way or conveyor belt.  In this post, I have called the wind felt due to current 'current wind' and I will try never to use the word current to mean 'now', just moving water.

In this situation the surface of the moving water only feels a very light three knot breeze and so it is likely to have very small ripples and so it would look lighter in colour like a calm patch.  When you sail, you sail by the apparent wind, so this really is a calm patch as far as your sail is concerned and if the whole course has the same constant current, it is more than a calm patch, it is a calm day.  In this case, the current only really matters at the laylines (of the marks and finish) and at the starts.  

Avoid undershooting the windward mark and try sneaking in on people at the leeward mark because everyone will tend to leave too much room around the leeward mark.  At the start there is likely to be huge line sag (take a transit).  Because you can't sail straight upwind, boats on starboard will tend to creep towards the port of the line as they try to stay up near the line causing pile-ups at the pin and openings at the boat end of the line.

Wind Against Current

 
Next let's take the situation where the wind and current are going in opposite directions.

This time the water is being pulled up into the wind so the surface of the water feels extra wind and so it will be choppier.  As far as the water at the surface is concerned there really are 10 knots of wind, so the water will be quite choppy.  Without a reference point, the only way that you may be able to distinguish current wind from true wind is that current, especially a change in current, often makes the water more turbulent which can make the water look particularly jagged and irregular.  We sometimes call it piranha water because in some cases it almost looks like piranhas are trying to poke up from the surface.  Once you get used to looking at turbulent water, you can often recognize current, but just because you can't obviously tell that there is turbulence doesn't mean that there is no current.

If the current extends across the whole course evenly, it doesn't affect strategy except, once again at the laylines and starts.  At the windward mark it is a good plan to undershoot the windward layline.  At the Gorge (Columbia Gorge Racing Association at Cascade Locks, Oregon) there is strong windward current because it is a large river.  In races and in training, I have undershot the windward layline extremely in the three boat length circle, but then just I could just go head to wind, retain my rights and wait for the 3+kt or so current to pull me up to the mark (if tacking would mean having to duck boats).  This way people can only pass me if they have drastically overshot the mark and can sail past my bow.  Of course it would be faster to anticipate the current properly and hit the layline perfectly, but usually everyone overshoots the mark by a lot and the Gorge often hosts big regattas.  When there is strong windward current it is important to brush up on your rule 18.3!  There are a lot of places to be gained.

At the leeward mark the danger is hitting the mark.  I have sailed almost completely past a mark in light wind with windward current, only to have the back windward corner of my transom hit the mark as my boat was pulled sideways upwind.  

At the start line it is important to be cautious in windward current.  My strategy is to get a good transit and the find a part of the line without much congestion.  When boats are close to each other they tend to get caught up with each other and get swept way over the line.  The Gorge is my favorite example of windward current, there is also sometimes upwind current in Victoria and Vancouver or West Vancouver, but it depends on the tide, so it is less reliable and often not as strong as the Gorge is literally a river flowing upwind.  While playing around with downspeed pre-start maneuvers in windward current, people often get excited when they realize that by lifting their dagger boards a certain amount, they can get the drag of the wind on their flapping rig to perfectly cancel the upwind thrust of the current.  However with your rig forward on your boat and your rudder aft on your boat, this strategy will tend to pivot your bow off the wind until you are on a beam reach or below.  If you are all alone this might be okay, but in a crowd it is a problem, you are asking to be luffed.  As soon as you need to avoid someone (and most people will be to leeward of you), you need to drop your dagger board to maneuver properly and then you get sucked over the line.  

The strategy that I have had more success with is to point straight head to wind and then try to avoid touching my boom and to avoid tacking.  At the Gorge there is usually plenty of wind to push you astern, so if you point your boat far enough upwind that your boom and so the drag of your sail flap inside the back corner of your boat, and then if you angle your tiller straight or slightly to windward, the drag on your sail causes you to drift straight backwards with attached flow on your dagger board and rudder.  What is more, unless you touch your boom or pass head to wind, you have right of way over most other boats.  You are on starboard and it would be hard to luff you since you are already pretty far head to wind.  If you accidentally tack, you are subject to Rule 13 and have to go back below close hauled and reset.  If you touch your boom then you are subject to Rule 22.3 "A boat moving astern or sideways to windward through the water by backing a sail shall keep clear of one that is not".  However if you are moving astern due simply to good clean drag of wind on your rig and you have not touched your boom (even with your shoulder the jury tells me) you retain your rights.  Unfortunately that may be a hard one to explain to the person that you reverse into.  Yes, technically they hit you from clear astern while you were minding your own business, but you better be able to prove that you didn't back your sail.  It is probably a good idea to warn them ahead of time: "watch out clear astern boat, I haven't backed my sail!"

The really cool thing about sitting on the line heat to wind, moving backwards is that to start going again it is relatively easy.  You gently push the tiller away from you to reverse onto a tight reach, sheet in and hike.  It feels weird because the flow on your foils has to switch directions, but it powers up quickly and unless someone is to leeward and bow out on you, you have a good shot at a good acceleration.

Cross Current

That was quite a segue, but at last we have arrived at the final scenario: current flowing across the wind direction.

The angle of the resulting apparent wind depends on the relative strengths of the wind and the current.  4 knots is pretty extreme, but imagining it helps you recognize what happens on a smaller scale with less cross current.  Also inspite of my best efforts, I found that my 7 knot arrow is too short or my 4 knot arrow is too short, but the apparent wind angle doesn't look too far off 30 degrees.

This math behind the 8.1 knots comes from the Pythagorean Theorem based on the triangle drawn above.  The true wind and the current wind don't have to be perpendicular, but if they aren't then you need even more trigonometry.

The angle calculation that gave us 29.7 degrees comes from the trigonometric function 'tangent'.  Arctangent is the inverse of tangent and it is just used to solve the equation.

Bla bla bla that is math not sailing...

What does it mean for sailing?

Again, let's assume the cross current is constant thorough the course and moving from course-right to course-left as shown above.  This often comes up at West Vancouver Yacht Club where the course is set up in deep, fast moving water if they can get their marks to hold.

If the race committee ignores the current when setting the course, then in the above cases with our 7 knots of true wind and 4 knots of cross current, the course would look quite skewed to the sailors and to anyone else who is not anchored.  Below I have made a slightly less extreme scenario with the apparent wind only skewed fifteen degrees left of the true wind.  Even so, as the diagram shows with the current pushing left you would hardly be able to make the pin.  A good race committee would realign the start line to take this into account, but this is tricky for them because sitting on the anchored race committee boat, their wind instruments do not pick up the current wind.

However, if the race committee squared the start line to the apparent wind by factoring in the current wind, the current will not only be pushing along the line, it will also be pushing up across the line which is dangerous for starting over early as we talked about.  Below is a diagram of the course squared to the apparent wind, notice the current's angle (because you certainly will when you are trying to sit on the start line). 

To deal with this current direction, I recommend taking transits and executing conservative starts.  There will most likely be several black flag starts and a pile-up at the pin.

The next question is where is the windward mark?  In my diagrams I have the start lines square to the rhumb line, but this is actually quite unlikely.  The race committee may or may not start with the start line square to the rhumb line, but they will probably move it around once the fleet starts getting general recalls.  

If the race committee set the course based on readings from an anchored boat in this current, the windward mark will be skewed off to the right.

Also, the starboard layline moves away to windward and the port layline comes down to leeward.  On the upwind, the boats will be pointing at about 40 degrees to the apparent wind as I have shown with the yellow boat in the above diagrams, but their 'course made good' through the water will be heavily skewed by the current.  You can imagine a boat sailing normally relative to the apparent wind, but then it is also being pulled sideways by a conveyor belt while the marks are not.

In the above diagram, there will end up being significantly more time spent on port than on starboard upwind, so when in doubt you should be on port.  You might just want to tack onto starboard if there is a particularly nice right shift.  In fact, even if the race committee squares the windward mark to the current-induced apparent wind, part of the current will be pushing everyone left and the laylines will still be affected, but because you now have a component of windward current added into the bargain, the laylines will come up sooner. 

As you near the port layline (being sucked left, that is the one you will probably hit), take a transit through the windward mark to see whether you are near being swept past the windward mark even though your bow points beneath it.  Remember, as always, it is very risky to approach the windward mark on port within the three boat length circle.  

The downwind leg will also be skewed, even more so if they have tried to compensate for the skew on the upwind and have nearly even upwind sailing time on port and starboard for the upwind leg.  

Since Laser downwind angles are pretty deep, you have to have thought out where you need to go before the downwind starts and to get a visual on the leeward mark.  If the race course was not set to the true wind rather than the apparent wind the mark will be farther to sailor's right than anticipated which is okay because you will be pushed right by the current anyway, so don't start by pointing at the mark or else half way down the course you will have to be pointing back the other way.  

If the course is set to the apparent wind then the leeward mark will look like it is in the right place off the bat, but if you forget about it while jockeying for position and trying to go fast, you will find that it has migrated sailor's left.  People forget that they are on the conveyor belt, so they sail straight down wind when they really want to by the lee or broad reaching slightly into the current so that their course made good is towards the mark.  Again if there is a transit available sighting through the leeward mark can help you keep track of whether or you are tracking towards the mark or slipping sideways.
 
Below I have drawn out the diagrams for cross current coming from course left to course right with the situation that the race committee has set the course either to the true wind or to the apparent wind.

In this case you would be able to lay the mark from the barge (maybe even from the pin with the current) except that you won't be able to star the race because everyone will be crowding the barge and actually being pushed up into it.  The poor race committee will almost certainly shift the course more like the diagram below.  However keep in mind that cross current is often fairly weak.  Imagine the diagram with half as much left-to-right cross current.  If it is a relatively small fleet and the race committee is good at identifying boats over the line, it could well be sailed.  Watch out for the barge when starting, think about the laylines, and try very hard not to hit the leeward mark.

This looks like a much more reasonable course, but still be careful about getting sucked up into the race committee boat and being pushed over the line by the current, as well as hitting the marks.  The leeward mark would be easy to accidentally hit, as I said before, but I should also mention the windward mark.  Unless you make a point of sailing past it before bearing off, you could easily hit the mark with the back of the boat as you exit the mark when there is cross current from either direction.

It would take too long and may be overly confusing to talk about all of the other permutations and combinations of scenarios where current is strong enough relative to the true wind for it to be significant, but I encourage you to get out some props: toy boats, arrows, maybe a sheet of paper that you can pull with the boats on it but not the marks to simulate current.  Also if you have a favorite scenario, particularly if it is common at a major event you have been to let me know and I could make another post about it playing through the scenarios at the critical points.

It is tempting to study these examples and come away with supposed rules of thumb, but the reality of cross current is that it is often localized, changing with time, or at different strengths in different places.  So it is generally true, in say an unpredictable gently oscillating breeze, that you want to sail the long tack first, and with cross current that means sailing into the current first, however when you sail into strong current, you don't make much ground.  Not making much ground is fine if the current is equal throughout the course for the whole time you are on the leg, but if the current is less somewhere else, or if somewhere else on the course the current is moving at a different angle, then you actually want to sail sideways across the strong current to get out of it and if you have to sail into the current, do so where it is weakest.  

The next layer of complexity is that currents are often weak relative to the effects of the wind, so all of this may be going on in the background but the person who wins may have completely neglected the current effects to focus on wind strategy.  Here is an example: there is a quarter knot of current relief on the right but there is a big persistent left shift.  The people who sailed right may have sailed a faster absolute speed because they were slowed down less by the current, but it could be that the people on the left on the inside of the big shift got to sail 50 boat lengths less distance and so they came out ahead in spite of the current.

Another point where people can tend to go wrong with cross current is that if you are sailing upwind with a cross current, it is tempting, especially if there is a shore that is moving in your peripheral, to fall into the fallacy that if you are footing you are just on a treadmill, but if you are pinching you make more ground upwind.  However, so long as the current is constant throughout the course, every sailor has to sail over the same amount of water that will pass across the course, so the part of your movement that is into the current is inevitable.  Don't pinch.  If you sail your fastest angles, at some point you can tack and cross the pincher.  You will do best if you can sail your fastest angles for as much of the course as possible.  That sounds obvious, but to execute it, it requires thinking ahead so that you don't spend the last part of your upwind or downwind leg on a beam reach trying to correct your course back to the mark. 
 
Happy side-sliding!  Let me know if any of you have stories about current in specific scenarios: building, dying, turning, current; localized current, tide lines, whirlpools, weighing off various wind strategies against current strategies.  I can't cover it all, but it might be nice to post someone's current story if there is interest.

Many of my craziest current experiences have come in and around Oak Bay.  Here is a link to Bob Britten's huge store or local knowledge about Oak Bay.  The last few movies include some super interesting current-related scenarios.

Persistent Shifts Part 4

Shifts are often modeled and thought of as sudden changes of direction, but this is not necessarily the case.  In the Sail Racer game we have a scenario where the wind shifts from the weather input are smooth and continuous.  So how do you decide when is the time to tack during a smooth shift?

If you dig out your strategy books you should find somewhere in there that you are supposed to tack when the wind passes the median wind direction.  For example, let's say that you are sailing on an exceptional shift, you are very lifted, pointing almost straight at the mark, but then then you get a slight knock.  You are probably still lifted overall (ie. you are above your median), so don’t tack yet.  Only tack when you have been knocked so far that you are pointing below your median heading because being below your median on one tack means being above your median heading on the other tack.

For a good illustration of how to tack on the median in a smooth shift, check out  this Speed and Smarts article posted on the Destination One Design website from which I pulled the picture below:

Click Here

Then follow the link:  'How to play oscillating shifts'

by Dave Dellenbaugh

at http://www.destinationonedesign.com/index.aspx?s=how+to+play+oscillating+shifts

This image is not mine, I found it by following the above link.  Please consider subscribing to Speed and Smarts if you like it: https://www.speedandsmarts.com/Order/Subscribe

The above picture shows how a boat tacking on the median would make gains on a boat tacking on the maximum.

It is nice to be able to put this theory into practice by playing the Sailracer.net wind game immediately after reading it instead of having to wait for the race on the weekend (or for the lake spring to heat up to put it into practice.

I don't know exactly what Sail Racer's algorithm is, but while playing the game the instantaneous wind trace line and a damped-down wind trace line are drawn out in grey.  The damped line is apparently averaging out the wind direction from the last little while.  With some exceptions, like approaching laylines, the Sail Racer algorithm seems to make the computer’s boat tack whenever the line that represents the wind direction crosses this damped average wind trace line.  This essentially means that the algorithm tacks on the median, but we don't know how the algorithm calculates the median.

I have noticed that for whatever reason, that in this game, the wind has tended generally to come back to North and to swing more or less evenly around the direction of North.  If I sail/play the game with that information in the back of my mind, my memory is going back much farther than the wind algorithm’s memory.  So when there are longer phase oscillations and the game begins with the wind direction off to one side, well to the East or West of North, I am usually able to win by being more patient or longsighted than the algorithm.  The algorithm gets impatient (so to speak) by deciding that the current wind direction must be the new normal and so it sets it as it's median and starts tacking on it.  On the other hand I sail the lift to get inside the next shift, that means taking deep breaths and waiting with fingers crossed for the wind to normalize back to North.  

In the screen shots below I am the red boat and black is the algorithm.  I took a screen capture of these races because they show an example of playing the long phase oscillation as a persistent shift by sailing on the lifted tack and waiting for the wind to (hopefully) come back to North (my long term median) before the end of the leg.  The computer in the black boat, blindly following the algorithm, assumes that the initial wind direction is here to stay and that that should be the median.

Looking more closely at the first screen capture you can see that when the race started the wind was already to the right of the rhumb line (slightly East of North) by looking at the grey wind trace lines.  I made a plan based on my theory that the rhumb line (North) was the true median.  The computer’s boat (black) took the North-Northeast direction to be the median wind direction and so she tacked on the short phase oscillations thinking it was a neutral phase.  Over the course of the leg, the wind eventually returned to my predicted Northerly direction, so my strategy of treating this scenario as a persistent shift paid off, I got well inside the long phase persistent shift.  However I want to emphasize that then crazy shifts came through (shown by the squiggly faint wind trace line), I tacked on them, I didn't just blindly follow my plan with no regard for the short phases that were extreme enough to pay for their tacks.  This is what I have been building up to with these blog posts, the idea that overall you may have a persistent shift strategy based on the big phase, but superimposed on that, you can still tack on the extreme oscillations that come through in the small phases as long as you get back to your plan as soon as possible and as long as your tacks pay for themselves (remember the bit in the previous blog about how costly tacks tend to be).

In the first example where the persistent shift was more subtle, I still tacked on the big shifts, but I made sure to get enough separation from black to be able to cash in my left side advantage if my prediction came true.  When the prediction did come true, I did not know exactly how long this big phase would last, so once I had big paper gains, I crossed back in front of the other boat then tacked directly to windward of her to make it more or less impossible to come back and pass me.  You can tell more clearly that I did the same defensive cashing in move in the second screenshot race.  This is an effective move not because of my wind shadow (no wind shadow in this game), but because tacking to windward of black removes leverage that she needs in order to gain or lose on wind shifts.

Paper gains mean the theoretical advantage that you have if nothing changes.  Until you have cashed in your paper gains, because of your leverage, a change in the form of a bad shift could make your gains vanish.  Cashing in means reducing your leverage: sailing ahead (or behind) your competition.  Once you have cashed in you have reduced your leverage and so you are not as susceptible to undesirable shifts.

What I have been trying to illustrate is that in situations with combined long and short phase oscillations, that is, with real world messy persistent shifts, you often have competing strategies: to get inside the (big) persistent shift and to tack on the (small) oscillations.  The trick first to identify whether there is a high likelihood of a persistent shift that could be capitalized on.  Next you need to get a feel for which oscillations are big enough that tacking on them pays for itself and which ones are a waste of time and leverage.  Another thing to keep in mind is where you need to go next so that if you find yourself in a neutral (macro) phase, you can act purposefully.  If you are happy with your placement on the course during the neutral phase you could spend your time tacking on small shifts.  If you are ahead your time in the neutral phase might be well spent cashing in any gains you may have by reducing your leverage.  If you have losses rather than gains, leverage is your only hope of recovery and it is laylines that are the enemy as time runs out waiting for the miracle shift to get you back in the game.  In that case you could decide in the neutral phase either to eat your losses by cashing in/consolidating your loss or to double down and go for more leverage.  Another use for the neutral phase particularly at the beginning of the leg is to start executing the overall strategy.  That could be getting inside the persistent shift, getting out of bad current or sailing to where there is better wind, for example.