With so many boats out racing, the fleets have spread out and we often face the situation where one fleet is approaching the finish line, while another is still rounding the mark for another leg. This can lead to potential collisions if the finish involves a starboard rounding.
In the diagram, boat A is finishing and boat B still has a leg to sail. On the left, with a starboard rounding, A and B are approaching the mark in opposite directions. If boats in B fleet have already rounded the mark they will be approaching A on a possible collision course. If the course is set with a port rounding to finish, as on the right, the problem goes away. Both A and B will round in the same direction.
This will also work for a downwind finish. Once the race is underway, the RC simply moves the boat to the other side of the pin, and you can end with a port rounding finish.
