Wouldn't black, being the inside overlap boat at the two-boat-length circle have bouy room? Plus isn't he the leeward boat? I would think Black had all kinds of right of way, but I've been known to total misinterpret the rules too. I always get those darn rule quizes wrong.
-Rob V.
18.2(b) OVERLAPPED AT THE ZONE
If boats were overlapped before either of them reached the twolength
zone and the overlap is broken after one of them has reached
it, the boat that was on the outside shall continue to give the other
boat room. If the outside boat becomes clear astern or overlapped
inside the other boat, she is not entitled to room and shall keep clear.
In other words, red owes black room at the mark no matter what happens after they entered the 2BL circle. Now, it's up to black if he can get there and use it.