That flight wasn't me, that was just a flight from Monday.
This was a very good pilot, and me
last year
Flight Details
Flight declaration was over 1000km, managed 880 (ish) claimed 775 as that was the nearest official turnpoint to where we had to give up due to weather.
Try Gliding at your nearest club, it's more than the "Up, round and down" than it used to be known for.
My glider has a Vne of 154kts and best glide of 60-1 (60 miles glide for every mile of Alt) at 65 kts, at 90 kts it is still doing better than 50-1.
If you look at the trace on the link above you'll see that some of it was done through controlled airspace (with clearance) with a ground speed over 300kph.