Yes, well, I can vouch for the huge wind shadow (vis a vis a small dinghy) of the Sandbanks chain ferry when trying to sail into Poole Harbour against the ebb and a north-westerly breeze. Without the ferry I would have made it. Still, it was good fun trying, and after frequent visits I got quite friendly with the circle of cormorants sitting on the nearest channel buoy.
David, thanks for the windyty suggestion. I've got it bookmarked.
Michael