Team Race - CALL J 04      

Rule 10 On Opposite Tacks
Rule 18.1 When Rule 18 Applies
Rule 18.2 Giving Mark-Room

Question
Boats A on port tack and X on starboard are sailing parallel courses on a run and are approaching a starboard-hand leeward mark. A is clear ahead when she reaches the zone. A slows and X becomes overlapped outside her. A now sails past the mark and luffs slightly. X has to change course and protests.
What should the call be?

Answer
Penalize A.
When A reaches the zone, she is on port tack and must keep clear. However, she is entitled to mark-room under rule 18.2(b).
At position 2, A is sailing her course to the mark and the obligation on X to give her mark-room remains.
After position 3, A is no longer sailing her proper course to round the mark. A must keep clear under rule 10, and by causing X to change course A fails to keep clear.