
Post by
karriv | 2014-12-02 | 22:19:50
Unfortunately it is not quite that simple;) Or fortunately, depending on your perspective, as IMHO the complexity is what makes this so interesting;)
The first thing to keep in mind is what Cvetan already said. In 99 cases out of 100 it does not make sense to sail a TWA worse than the optimal VMG TWA, but rather tack and gybe. So in this case TWA<47 and TWA>142 would be no-go zones.
Now, asking whether you are on VMC would be like asking whether you are driving your car at a speed. Yes you are, the question is actually "What is my VMC?" and "Is that the max VMC possible?" The answer to the first question is simple, just apply the formula I gave. The answer to the second is a bit more complicated, you would need to do the calculation with multiple COG values and the pick the one with the highest VMC.
This would be the end of the story if the wind would be constant everywhere (well actually not, but quite close to the end;). But it's not. So again, when you have a long distance to cover to the next mark, very seldom the max VMC course is the one you want to sail. Which brings us to the next question "What is the optimal course I should be sailing?". And that, boys and girls, is the million dollar question this game is all about;)