Ok, given the assumption that they are racing, who had right of way? They appear to be both on port tak- Is it windward boat must keep clear? Or did the big boat such switch onto port to try to avoid collision? A painful lesson in racing rules me think....
It was the Fife ketch Sumurun sinking the NY30 Amorita in the Tiedemann Regatta off Rhode Island in 2007. Sumurun was overtaking 2 smaller yachts (Alura and Amorita), all on the same tack, close to a mark. Sumurun cut it too fine, and hit Alura's boom. This sheared Alura up to windward, striking the leeward quarter of Amorita, who in turn was spun round into Sumurun's path. Amorita was virtually cut in half and sank immediately: luckily nobody was killed, but it was a very close run thing. Footage of the incident is at the end of this clip http://www.youtube.com/watch?v=wNROcoFLIVo.