RE: what fin size for a 6.8m on a S type104
Yeah, it's kinda big. But in reality the new fin tends to ride "small" for it's mechanical size, so a 34 really was more like a 32 etc. And yes, I am also the first to note you can also OVERfin an ST pretty easy.
I'm personally guilty of loading the stock05 / 32cm and 06/33 in the 115 and just leaving it at that for personal / fun use..
Although visually the 2007 ST's look similar to previous, the new ones have a lower nose, flatter and faster rockerline, basically derived from the S85.
Cheers ~ Ian