They're DS sails.
i had a sail in Elenor which was fab. The kite is quite flat when compared with the fyfe cut but unlike the old caws shape you can allow them to curl and then sheet back on. In comparison to the E5 the ride is much smoother and the boat accelerates from displacment to planing modes smoothly without trying to chuck you offf the back end. It felt planted and safe. Because the ride is smooth it didn't feel like we were going so fast. I may be worth sticking a GPS on for the trials to show the true speed.