AC Racing Rules of Sailing penalty line

[NevP 0]

So who else gets confused with the penalty line rules for the AC? Section 44.2 http://noticeboard.americascup.com/wp-content/uploads/2013/08/ISAF-Racing-Rules-of-Sailing-AC-Edition-v-1.19..pdf

 

I figured I'd be a sad b#####d and try reading the rule book.

 

I think I get the general idea. The guts of it seems to be, a penalty line is initially placed 2 boat lengths behind the infringeor or infingee boat depending on the cicumstances, the line then advances at percentage of the "universal VMG / VMC based on the wind speed and direction, current, and course to the next mark". The penalised boat must slow and drop behind the line to clear the penalty.

 

So what is "universal VMG / VMC"? There is no definition (or even any other mention) of this term in the rules and a quick Google didn't come up with any answers. Is this common knowledge or something madeup for the AC?

 

OK. So "VMG" I get. Velocity made good wrt true wind. "VMC" I think refers to velocity made good wrt the direction of the current leg (used for reaches on the start and finish legs when VMG doesn't make sense).

 

But how do they come up with "universal"? Is this;

a) Current/projected/average for the penalised boat?

Current/projected/average for the infringed boat?

c) A thumb suck based on arbitrary polars for a theoretical boat/AC45/AC72?

d) Something else?

[Guest]

(bump)

[Island Time 1,246]

The "Universal VMG/VMC" is taken from a set of polars for current wind speed and Dir by the umpires. At bit about it here http://www.catsailingnews.com/2013/07/a ... lties.html

[otto 31]

Thanks for that link IT

Here's a vid which doesn't explain the penalty but helps shows how they get to hit.

Lot more in the back ground than I thought.

 

And check out the umpire boat

 

http://www.youtube.com/watch?v=Xt1uyJxlaY0

[Guest]

Thanks IT.

 

via a response on SA, the current polars would appear to be here; http://noticeboard.americascup.com/umpire/ac72-penalty-polars/

 

Anyway, the upshot seems to be that in downspeed situations (as per NZ's rounding the other day) a penalty may not actually affect the penalised boat...