On a kayak it is tough. The water is not very deep. It may look deep but it is not. You may find a couple of holes but for the most part it is pretty shallow. Fishing it can be like anywhere else, it is either on or it is off.
Never fished it but my brother lived there and we used to take the kids out there swimming. That was 15 years ago and the river changes ever year after the big rains. Back then the east side of the horse shoe by the boat ramp was the deeper side. They used to ski over there. The west side had the shallow swimming holes. The south side or bottom of the shoe was less than a foot all the way across. Wide and shallow. If my brother still lived there I would be all over that place finding the fish in my kayak.
Ditto what Todd said. You'll find some deeper holes on the east side of the bend. It can still be fun to wade the shallow sandy west side and fish the channel along the west bank for small bass. The sandies will still move up into those shallows but they are def not as plentiful as past years when Granbury was full and more fish could move up. My Family has lived out there since the early 80's and I explored every inch of that bend as a kid. Even though I have convenient access down there I hardly ever make the effort if that is any indication of the fishing.