Several questions about sailing in light winds

Hi all,

I'm following Volvo Ocean Race intensely, since a member of my country is racing in Team Brunel.

Itajai In-Port Race was very interesting display of these huge boats sailing in very light, sometimes almost non-existent winds. I've already gathered quite a lot of knowledge on light wind sailing, but there were few things sailors onboard those boats did that I do not understand.

For example, in these light winds, after tacking, gybing or stopping dead, they never ever ease out mainsheet, not even on reach or downwind. Even with the boat at complete standstill, they do not let the sail out. Every sailing resource I ever encountered says that if the boat is stationary or moving slow, you have to ease mainsheet out to re-attach the airflow, and as you gather speed and apparent wind comes up, you sheet in.

Now I know that these boats often sail faster than the wind, meaning that even on downwind legs, apparent wind comes up front, so it's logical to sheet in almost all the way in. But it doesn't make sense when boat is stationary and airflow is clearly separated.

So, why do they do that, while are they keeping sail sheeted in all the time, even when it's clear that apparent wind hits the sail at 90° angle? Is it because it would take too much of a physical effort on sailors to ease and sheet in such a massive sail?


And another question. It seems logical to have as much sail area spread on downwind leg as possible if the winds are extremely light. However, I've seen on several occasions, some of the boats choosing jibs instead of Code Zeroes for the whole downwind leg. Commentators also noticed that, but didn't explain why is that done. It makes no sense to me - why would you choose small sail with such a light wind on downwind so far from the gate?

Could someone more experienced than myself comment on these intriguing tactical choices?