If I were Blue, my first inclination would be to slow down just enough to let Yellow and Green cross. Then I'd accelerate past their transoms, and hopefully roll gray while she gybes. That would put me to windward for the reach to the finish.

There is some risk in that move, though. Gray is inside overlapped right-of-way boat at the mark and Blue is not entitled to mark-room. If Blue can't roll Gray, then Gray could force her up above the mark.

Regards,
Eric