Question
The situation occurs in the pre-start, with approx. 2 minutes to the starting signal. The committee boat is also a starting line mark.
Between situations 3 and 4 Blue makes a big and rapid change of course, backing her jib to bear away and does not give Yellow room to keep clear. There is contact between Blue and Yellow. Both boats Y-flag. What should the call be?

Answer
Penalize Blue. Rule 18.2(d) only applies after the starting signal and never at obstructions, so when Blue changes course she must comply with rule 16.1. Blue is a right way boat changing course. She did not give Yellow room to keep clear and broke rule 16.1.