Hi there, yes know the Gorge well, even for myself as a fairly experienced wave sailor, often on 3.7/3.4 with 78kg's on the good days. Does the Quatro feel ok in volume/do you think you could handle less? normally not an issue with the XS, which is pretty much designed for people your weight/size. A Quad will almost always give you more control than a single fin in overpowered conditions, as they sit a bit deeper/flatter in the water, so even the 68 could be an option if you want a bigger range. The XS is really popular in Pozo/Canaries, a similar high wind location to the Gorge. I think with the 68 you'll cover more sail sizes, esp up to 4.5 or so probably, the XS will be perfect for 3.0-4.0 probably?