20.1
Hailing
A boat may hail for room to tack and avoid a boat on the same tack by hailing ‘Room to tack’. However, she shall not hail unless
- (a) she is approaching an obstruction and will soon need to make a substantial course change to avoid it safely, and
- (b) she is sailing close-hauled or above.
In addition, she shall not hail if the obstruction is a mark and a boat that is fetching it would be required to change course as a result of the hail.