I don't understand why Mr. Curry thinks the Wave (or any "slow boat") was "the Problem". Any time you have any boats going upwind, while spinnaker boats are coming downwind, these things can happen.
We nearly T-boned Mike Krantz while we were coming downwind at high speed and we too were activly looking for other boats coming at us all day long. But we never saw him as we were also having a -developing situation- with a boat in our class as we converged on opposite gybes, and we were hailing him "Starboard".
Mike was below our kite coming upwind fast, so we never saw him, or heard him hailing us, as we were looking the other direction at the converging boat to our right, when all of a sudden, from behind the kite, out pops Mike, about 20 feet in front of us.
Luckily for all of us he was in the process of bearing off to let us by when he didn't see us bear away, and as soon as Andi saw him he pulled the tiller and slammed our bows down, sending me for a trip to the bow and back. Ask Seth about that!

There have been plenty of other similar incidents at most regattas with a good turnout. I never assume the other guy sees me unless I see his eyeballs and he waves at me, and me at him. We were damn lucky Mike moved for us or it would have been very ugly.