Saturday, November 30, 2013

Sailing in Dirty Air?

You have probably heard some respectable sailor or coach say "never ever sail in dirty air," or to "always tack out immediately," but while that is a great guideline the absoluteness of these statements are misleading.  There is a common picture that I would like to paint of a big fleet.  Let's say you are sadly not bow out, or that you are in second row in a crowd of starboard tack boats coming off the line who are all in dirty air and who are all going to the correct (in this case left) side of the course.  The first move for me is not to tack, it is to quickly read the body language of the person or people who are giving me the worst dirty air.  If they are antsy, squirming looking over their shoulders again and again, you might hold on in their dirty air because they are about to tack out and give you clean air.
If you are the yellow boat, you are still in a fairly bad situation after the blue boat tacks away, but having waited for them to tack, you are in a much better situation than if you had immediately tacked and ducked the red boat, and the last light blue boat at which point you would be last and going in the wrong direction.

On the other hand if the boat giving you the worst dirty air is settling in, hiking hard and focused you will probably have to tack out or foot off to get out of there.  But before you do this, look at the body language of the boat that is pinning you or the boat that you will have to duck if you tack onto port.  If they look like they are about to tack then wait for them to tack and then tack with them.  If you tack with them, not only have you avoided having to duck them, they can now act as a buffer boat for you.  If someone calls starboard on them they will have to call to you for room to tack early enough for you to be able to tack.  They will probably lee-bow the starboard tacker and even if they don't you might be able to lee-bow them, and there is a chance that in this position you will get the original starboard tacker's, or your buffer boat's starboard tack lane (remember that we are assuming that the left is the correct side of the course so getting onto starboard in this way is good).  On the other hand if your buffer boat decides to duck the starboard tacker, you are within your rights to call for room to duck, and if you can get a good rounding of the starboard tacker's transom* you end up on the same ladder rung as your buffer boat just like in a rabbit start.  Then you can tack back onto the favored tack as soon as there is a lane to tack into and you get first pick of lane because you are pinning your buffer boat.

Going back to the situation of being stuck in a crowd of starboard boats in dirty air all going the same (favored) way, if both the boat upwind is not going to tack away and the boat to windward pinning you is not about to tack and act as a buffer boat for you, then you need to crane your head and look to windward and astern of this windward boat to look hard at exactly which boats you would have to duck, cross or lee-bow after you tack and what kind of a situation that will put you in.  Because of the 'rule' that is often seized upon about tacking immediately when in dirty air (which is great advice in most situations) there are a huge amount of sailors who will tack immediately after realizing that they are in dirty air without (quickly) planning their escape properly, so after their immediate tack, they proceed to do a series of poorly executed emergency maneuvers (especially in breeze), dropping their mainsheet to be able to duck, throwing in out-of-control crash tacks into even worse positions etc. all because they didn't take the time to quickly plan out or visualize what exactly bailing out is going to involve and where in the grand scheme of the fleet they will end up having to sail (maybe they will get to sail in clean air but on a side that has a crippling tactical disadvantage).  So if you are going to tack, first crane your neck to see what it will involve and plan your escape route, making sure that you are psychologically prepared for the boat-handling that will be required directly after the bailing-out tack.  I say 'if' you are going to tack because there are still some other options if sailing to the wrong side looks very bad.  Once you have assessed how much disadvantage (or advantage) bailing out will cause you tactically, you should always examine the alternative of footing off drastically or even reaching into clear air.  It could be that if you reach through one boat's dirty air to the clean air downwind but bow even with (that is abeam of) a boat that was giving you dirty air, you may then be able to hold that position relative to the lead boats indefinitely in clean air.  Although you are one ladder rung down (ladder rung being an arbitrary measurement), you might be one of the first boats in the group to get to the shift or the pressure or the current relief etc. that lead everyone to go left in the first place.  Reaching or footing drastically will obviously lose you ground, but you must compare that with how much ground you anticipate losing by tacking out and ducking and sailing away from the tactical advantage.  You should also compare the cost of bailing by tacking and the cost of footing off for a lane against the (terrible) disadvantage of staying put in dirty air.  In rare situations it could be that if you tough it out for 15 seconds in dirty air the whole fleet will tack on a shift (onto port) and you can either immediately tack into a clear lane if there is one or hold off with your starboard rights for a boatlength or two and then tack into the next available clear lane as it opens up to get back in phase with the shifts.

So the last thing I should be telling sailors going into a big fleet scenario is to sail in dirty air.  In fact I'll say straight out: Don't sail in dirty air!  But having said that, when you find yourself starting to eat dirty air quickly think ahead, quickly predict what is about to happen, quickly think through your options and make calculated decisions (that you can evaluate later).  As always if none of your options are any good, take a step back and look at the decision that you made, consciously or unconsciously before that situation that led you to be in the position where all your options were bad.  Maybe you could have made different decisions earlier about where to set up on the line.  Maybe you could have decided to pull the trigger 5 seconds earlier so that you were not shot out of the front row and so on.

*I just want to back track a bit to the asterisk at the starboard tacker's transom.  I said 'if you are able to get a good rounding'.  Now that may be a big 'if'.  If your buffer boat is not giving you a huge amount of room to duck the starboard boat and if you have to bear off significantly to get behind the starboard tacker's transom it makes it hard to get back up to close hauled without putting yourself in a position where you will be lee bowed by your buffer boat).  The solution is a trick that I picked up from the RYA Tactics book, but it is difficult to execute.  Rather than reaching down and calling for room to duck from your buffer boat, RYA Tactics has you seeing the situation coming early and with room to spare, before the starboard boat is converging perilously with you, you luff up, converting some of your speed to upwind distance, and then you bear off to get back up to speed and make a nice rounding on the starboard boat's transom.  In this way you are still on the same ladder wrung as your buffer boat, because you could think of it like an even rabbit start off the starboard boat's transom, but you are further to windward of your buffer boat so you keep a lane between yourself and them and you avoid being lee bowed.

1 comment:

  1. I made the .gif animation at the top with a really cool program that you can download for free from

    So I would like to promote the program because it is really cool and it is a great way to learn about rules and tactics and to practice placing boats for protests. I wanted to animate all of the examples that I talked about, but unfortunately I had trouble with the animation. It could be me, I am not the savvy, but I couldn't figure out what I had done wrong. I don't think that the program is quite ready to animate this many boats doing so many things at the same time. But I believe that it is open source so if any of you are super-programmers, please play around with the program to get the kinks out so that I can post more stuff like this!