Eric,

Just a question on obligations here.

Every boat in line knew the wall was close. Boat 1 turned and hailed that they needed water and were going to tack. They did not specifically hail any boat, but it was heard down the line to at least the 6th boat. #2 and several others immediately initiated their own tacks to get clear. At the time water was called for 1 and 2 should have been clear. 3 rode the wind change and then forced the now port boat back into a tack. If formal hails were given and time presented for a response, literaly they would have almost had to start before the gun sounded if more than 2 boats were involved and they had to be handed down the line and not just generally hailed by the lead boat.