CALL UMP 37              

Rule 11 On the Same Tack, Overlapped
Rule 16.1 Changing Course
Rule 18 Rounding and Passing Marks and Obstructions

Question 1
In the pre-start, blue and yellow are overlapped on port tack, with Yellow as the leeward, right of way boat. They approach a continuing obstruction on courses that make it clear that Yellow is the inside boat, or at an angle of approximately 90 degrees to the shoreline so that it is unclear which boat will be the inside boat when they reach the obstruction. Yellow begins to luff or maintains her course and Blue keeps clear. When Yellow is approximately one and a half lengths from the obstruction she suddenly bears away and passes the obstruction to port leaving Blue clear astern. There is a Y flag. What should the call be?

 
Answer 1
Rule 11 applies, and rule 18.2(a) applies when it becomes clear that the boats are about to pass the obstruction on the same side. Yellow has right of way and can choose to luff or bear away as she pleases provided she complies with rule 16.1.
If Yellow and Blue bear away to pass the obstruction to port, Yellow must give room to Blue while the boats are overlapped. If Blue becomes clear astern, she must comply with rule 18.5. In the situations shown, no rules are broken.
Display the green and white flag.
Question 2
In the pre-start, Blue and Yellow overlapped on port tack approach the outer end of a dock. Before the boats are about to pass the obstruction on the same side, Yellow, to leeward, luffs slightly and Blue keeps clear. Yellow suddenly bears away, leaving the obstruction to port. Blue leaves the obstruction to starboard.
There is a Y flag. What should the call be?

Answer 2
Yellow has right of way and is not the outside boat. Therefore, she can choose to luff or bear away as she pleases provided she complies with rule 16.1. Display the green and white flag.