We lift both when possible - but the leeward board is more important...sometimes, if time doesn't present itself, we lift only the leeward board and get the other one on the next gybe.

It was blowing about 15 to 18 in those races. If you can see it in the video, we had our boards raised about 8 or 10" upwind too. The boat carries enough speed at those wind strengths that the boards are more effective and we didn't need all that board grip in the water...not only does it reduce the drag, but it helps to settle the boat down just a little by raising the center of lift and making the boat a little less tippy.

As to the perfect aspect ratio - I have no idea. Over the last 15 years, we've seen boards continue to get skinnier and longer. The latest F18 boards are over 6 feet long. The A-cat boards have also seen the same trend (until the last couple of years where the a-cat boards are all banana shaped). The trick is a compromise between slow speed handling (pre-start) and efficiency at speed. Longer narrower shapes (like an airplane glider) are better at producing efficient lift. Materials have mostly driven the aspect ratio of our foils - which is why we're seeing them become thinner and longer lately (more advanced use of carbon). I'm sure there's a point in there where high aspect ratio becomes a problem...but I can't image where that is.