Part 2 — When Boats Meet

Section C — At Marks And Obstructions

Section C rules do not apply between boats when the mark or obstruction referred to in those rules is a starting mark surrounded by navigable water or its anchor line, from the time the boats are approaching it to start until they have left it astern.

20.4

Additional Requirements for Hails

(a) When conditions are such that a hail may not be heard, the boat shall also make a signal that clearly indicates her need for room to tack or her response.
(b) The notice of race may specify an alternative communication for a boat to indicate her need for room to tack or her response, and require boats to use it.

Rule 20.3

When a boat has been hailed for room to tack and she intends to respond by tacking, she may hail another boat on the same tack for room to tack and avoid her. S...