Lake Powell is is fighting with Lake Mead for the biggest man made reservoir in the Unites States. It all depends on the water level.
Since we just had a morning to visit in our tight schedule, we used the opportunity for some Kayaking. It was very nice to be able to go into some of the fingers of the lake. Just going with a group of 3 Kayaks, one being occupied by the guide was also pretty nice. The way back to the beach however was very strenuous because of the strong headwinds. I had to fight heavily but managed to get out again in the end.