That is a good read from the photo Reefman, but if you are actually standing there, you will notice the difference.
The sandy patch is actually the only break in an otherwise completely rocky bottom, in other words, the deeper patch of water. The white water on the surface is caused by a rip coming off the rocks through this channel.
I would rather cast into the channel leading out of the gully, or the channel at the back itself. Either way, still a brilliant spot.