I'm guessing it has to do with apparent wind direction? Allthough the 18' skiffs are very fast, I don't know what their angles are. I know that even when we go downwind fast on a Cat, our apparent wind is well forward in a good blow, not light air. Rick has made the case for hooters instead of spins for cats and the Volvo 40's are also using hooters instead of spins. I don't know why we don't see those on the 18' skiffs though.