Thanks to Litoralis, Pat and Captain JP for some answers to the question about how do you find out if you are racing in a persistent shift or oscillating shifts.
At the Dave Dellenbaugh seminar, the answers that emerged from a discussion with the audience (or at least the ones I remembered to jot down) were ...
1. Keep a record of wind readings. Dave recommended doing this on a port or starboard tack, preferably starboard, rather than going head to wind to check wind direction. The reason is that it is important to know immediately after starting the race (having just executed that perfect start you learned from tips 2 and 3) what is happening with the wind.
As Pat said, this is the most obvious way to check out the wind before a race and one that most of the racing books recommend. But how many dinghy sailors actually do write down the wind readings before the race? OK, there are practical difficulties in a small boat like a Laser. The usual recommended practice is to write the wind readings with a chinagraph pencil on the deck. But I think I can only remember a couple of occasions in 25 years of racing Lasers and 15 years of racing Sunfish when I have seen someone after racing with those telltale scribbles all over the gelcoat. So what's going on? Do people remember the high and low readings in their heads? Should I start writing down the numbers? If nothing else it might psych out the opposition ... or perhaps brand me as a hopeless geek. Who knows?
2. Check the weather forecast. Litoralis recommended this one. Often if there is likely to be a shift in the gradient wind, or a sea breeze, the weather forecast will predict it. Not always that accurate with respect to exactly when the shift will happen in my experience but better than nothing.
3. Watch another fleet. Dave suggested that in an oscillating breeze you can see boats in another racing fleet sailing at different angles at different places across the course. On the other hand, in a persistent shift you will see boats on one side of the course lifted more. Sounds easy, right?
Well, maybe I'm not looking for the right things or maybe my eyesight just isn't so good any more, but I've never been able to make this one work. At major regattas where there is another fleet starting before mine, I usually hang out to the right of the committee boat and watch their start. Sometimes I pick up clues about which end of the line is favored, but I've never been able to work much out from watching them sailing upwind for several minutes. Anybody able to give me some clues on this?
4. Watch the appearance of the water as Captain JP also suggested. If you see a lot of puffs and lulls on water then expect to experience oscillating shifts. If you don't see any variation of wind strength on the water (or a discernible single wind line) then expect a persistent shift.
5. Wind direction. If the wind is from the north-west, (we are in Connecticut Toto) or off the shore, then expect oscillating shifts. If the wind is off the ocean, then a persistent shift is more likely.
6. In a persistent shift boats on one side of you will gain on you. In oscillating shifts you can gain or lose against boats on either side of you. So watch the other boats; if all the gains are on one side of you, go that way.
For me, this one also falls into the category of "sounds obvious but I've never been able to see a fleet that way". What am I missing? Why do I find it hard to spot things like this? How do you tell whether a boat a quarter of mile to your starboard is gaining or losing on you?
Litoralis had one that Dave didn't mention: watch what the race committee are doing with the windward mark between races. Well done!
We are now half way through my ramblings about Dave Dellenbaugh's seminar on Top Ten Tactical Tips. Coming up ... two more tips that are mainly about sailing the beat, one on finishing the race, and a couple of more general strategic points.
And so let's move on to the next tip in the series.