Rule 20 (Room to Tack at an Obstruction) has a small but important change.

Rule 20 is previous rule 19; it is the rule that allows a boat to call for room to tack at an obstruction and requires the hailed boat to respond in one of two specific ways. The rule prohibits a boat from hailing when safety does not require her to make a substantial course change to avoid the obstruction, or if the obstruction is a mark that the hailed boat is fetching (see rule 20.3). However, it now states that when a boat is hailed, she *must respond* by tacking or hailing “You tack” (see rule 20.1(b)), even when the hailing boat has hailed when she is not allowed to under rule 20.3 (see above). This is for safety. To be clear, if the hailed boat thinks the hail is not allowed, she must still respond; if she doesn’t, she breaks rule 20.1(b) and will be penalized. After responding, she can then protest the hailing boat, who should then be penalized for breaking rule 20.3.