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Any real sailor is still drunk at the 10am start of a saturday seminar and Peter Isler is a very real sailor

@Glenn Watson No, I think you are missing the point. Yes the pin end boat is further to the relative windward, but in this scenario the frame of reference has the water stationary, and as such the mark we're aiming for is not only far upstream, but constantly moving at 2kt eastward. The ideal crossing point into the current may even be to the east of the boat starting at the committee boat end. Let's work out some figures as an example (I'm assuming more of a club fleet boat than an AC75 below) Assumptions: Angle of beat 45° to true wind relative to water (rtw) Speed of boat on beat half of true wind speed (rtw) Consider when boat in current on Port tack True wind speed (rtw) = sqrt(10^2 + 2^2) = 10.2 angle of wind (rtw) = atan(2/10) = 348.7° velocity of boat (rtw) = 5.1 kts @ 033.7° VMG northwards = 5.1 cos(33.7) = 4.24 kts VMG eastwards = VMG over water - current = 5.1 sin(33.7) - 2 = 0.83 kts velocity of boat relative to mark = sqrt(4.24^2 + 0.83^2) @ atan (0.83/4.24) = 4.3 kts @ 011° You should cross into the current 191° south of the mark, (I'd go for due south to allow for lulls when you may drift westwards). If (as you should) you are going for 191°, starting at the middle of the start line, you should tack onto port at just under 30% of the beat (assuming that the current starts at 50% of the way due north to the windward mark). Slightly earlier if starting at the pin end, slightly later if starting at the committee boat. There is certainly no advantage to either end of the start line.

In summary the pin end boat is further 'upwind', but they have both massively overstood the mark.

@@petermcfarlane529 I would not have used as strong words as you do, as you have made some assumptions that may not be right... In the video, Peter indeed states that the boats have not reached the layline yet when they hit the current. That's contradictory to your assumption, which I guess is that the boat of the left has passed the layline. So even though the layline is perfectly calculated with a sweetspot at 11°, you don't know where this mark is, other than that neither are yet on the 11° line to the mark. To your account, Peter said the boats hit the current half way up the boat, which indicated that the boats are on the layline by this time. But for what we know, then RC may have accounted for the current, and placed the mark far left. Anyway, the points is that a current generates a wind shift, and when sailing into a cross current going left you experience a left shift and should tack to port.

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I know

Because a current that is right to left, generate an apparent wind coming from the left (west). Imagine the same current of 100kts...like being over a train. You will feel the wind coming from the opposite of the direction of the train itself...that is...from left to right. So, because of the vector sum, because the current has added a westerly component, the resultant shift will be to the left. For the sake of clarification, the wind from 360 will appear from 350 (no precise calculation has been made).

@trainspot74 responded to your first question. Your second assumption is that the boat on the pin would stay longer in the current than a boat starting at the committee boat end. No matter what end of the line you start, or what tack you are at, you will reach the current exactly at the same time. This means the boats spend the same amount of time in "universe 1" with wind from top. And they spend the same amount of time in "universe 2" with a wind shifted to the left, until the pin starter has crossed ahead.

that is the way on etchalls shilds ands others classes j24 AND J70 you can have feet over the rail tho only 2 people allowed over the rail also no one can be in the boat only in the pit half out and thats only on a down wind leg and no one may move past the mast on the bow

www.northsails.com/sailing/en/2016/02/wing-on-wing-2

It's very hard to say it's totally wrong, however, I'd agree I wouldn't really call this 'starting tactics'. What he's really explaining is that when the boats hit the current, they will experience a left hand shift and boats further left will gain. That is absolutely correct. However, what I feel he's trying to emphasize here is, if you see a gain by getting yourself left of the fleet, starting left on the line sets you up to take advantage of that later in the beat.

The explanation is actually totally right. It seems like you have made some wrong assumptions... It is not a band of current. It is constant current from the middle of the beat and all the way up to the mark.

Vectors are correct. Right to left current creates apparent wind from left. You then add this apparent wind vector to the true wind to get the shift.

Actually it was planing for most of the video, it dropped of the plane when gybing, then got on the plane again. But as for the title, yes it was misleading as it was just a well executed gybe, nothing special or overly impressive.

The vector calc is correct. You have a 2 knot current pushing the boats right to left, they therefore feel an apparent wind from the direction they are pushed toward. The addition of this tidal induced wind from the left skews the true wind left. A left hand shift favours the left hand boat. The degree of shift will depend on how windy it is (more tide and less wind = bigger shift, less tide more wind, smaller shift).

It's more about the lay lines than the time in the current. (remember that the boat, in the example that started pin end had a better lay line and could tack and immediately be out of the adverse current). If it doesn't make sense, maybe try reading this: www.teameclipseracing.org/forms/Performance%20Racing%20Tactics%20upwind%20strategy.pdf

Woah.... I have no idea what you said but.. woah, Thats hardcore. Lol

bullthrush Thank you that was killing me!

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He started drawing the vector correctly, so he designed it on the wrong side of the wind. According to him, one will experience a left shift, wrong! With the vector on the right side it will be the right shift. Boat launch best!

@@ILLEMORO1 No, he draws the vectors correct. The tide is taking you from right to left and this creates an apparent wind from the left. A tide coming from the right, will make the wind feel like it's coming more from the left. So, the video is correct. If you're heading in to an increasing side current from the right, you want to position yourself to the left of the fleet.

It is counter-intuitive but he said it right

@Paul Hanly is correct: Assumptions: Angle of beat 45° to true wind relative to water (rtw) Speed of boat on beat half of true wind speed (rtw) Consider when boat in current on Port tack True wind speed (rtw) = sqrt(10^2 + 2^2) = 10.2 angle of wind (rtw) = atan(2/10) = 348.7° velocity of boat (rtw) = 5.1 kts @ 033.7° VMG northwards = 5.1 acos(33.7) = 4.24 kts VMG eastwards = VMG over water - current = 5.1 asin(33.7) - 2 = 0.83 kts velocity of boat relative to mark = sqrt(4.24^2 + 0.83^2) @ atan (0.83/4.24) = 4.3 kts @ 011° You should cross into the current 191° south of the mark, (I'd go for due south to allow for lulls when you may drift westwards). If (as you should) you are going for 191°, starting at the middle of the start line, you should tack onto port at just under 30% of the beat (assuming that the current starts at 50% of the way due north to the windward mark). Slightly earlier if starting at the pin end, slightly later if starting at the committee boat. There is certainly no advantage to either end of the start line.

@@drzeitnot Looks like you made some assumptions that are not correct... You base your conclusion that the boats have to tack to port before they reach the current in order to fetch the mark. Neither boat has reached the port layline when they hit the current. All boats hist the current at the same time, and as you pointed out, all experience a 11 degree left shift. The boat furthermost to the left would of course benefit most from this.

agreed