We have been several times on the 7 to 10 knots on the GPS, and sustained (this is about 8 to 12 mph). But it was helped by the current. Measured over the water (I have also a speed/log/temp-meter), the speed was 5 to 7knots.
This was with the jib and mainsail reefed (I only have 1 point), winds about 5B gusting to 6B (23 - 29 mph) and running (about 140 - 150 off the wind). Waves about 60 to 70 cm (a little bit more than 2 feet). Full ballast and all the crew on board.
The memory that everyone has of this day is a very nice sail

, as oposed to one day with the same conditions, but reaching

, heeling as crazy and geting a lot of water in the cockpit due to the bow entering in the waves, and the wind projecting the water to the back of the boat.
Unless I want to get divorced

, I would not dare to try to fly in 5B or more the spinnaker and try to make our Culzean beat her own sail speed record.
Fair winds,
Miquel
Culzean
I