1. eupho try to pass outside zone, shura keeping clear 2. shura manages to put the bow in the zone, eupho gives mark room 3. shura sails too deep, leaves the door open, eupho takes the room that is offered 4. shura probably not able to close the door, but could luff more, eupho keeping clear 5. after tack, eupho clear ahead, overlap established from clear astern, shura needs to give room to keep clear under 15