Thanks bomberdave - yes, its a good point.
I couldn't find any good information on wind speed, so I decided to run a 1km downscaled atmostpheric model over the lake for a year just to get an idea and calculate a few stats. Just in case anyone is interested in the future, the first plot is mean wind speed, the second 90th percentile wind speed and the third is a wind rose at Goughs bay. This is very quick and dirty, and as I say only based on 1 year of data, but it looks like there is a 10-13knot SSE wind with some regularity. Overall I was quite encouraged!