Quote Originally Posted by Dhampir
I'm saying it's in awful good condition for being at the bottom of a river. Marble is a very resilient stone, of course. But, I look at marble statues all the time and even after less than 200 years, they're showing the wear of being rained on and buffeted by wind. It seems to me that being at the bottom of a river, having the constant abrasion of water against it for 2000 years would remove at least some of the detail.
I disagree. If buried in the mud then being at the bottom of a river is an excellent place to preserve archaeological material. Look at all the great stuff that has come out of the Thames, for example.

I haven't been to the Rhone, but I do know that Arles in the lower stretch of river and that the Rhone is a fast river, historically prone to flooding. Floods deposit soft muds in the lower stretch and surrounding floodplain (which in time gets reworked by the river, so this statue could in fact have spent 2000 years near but not in the river until erosion freed it again).

As to the identity of the bust, I cannot say, but very few of the lines and angles and proportions of the face look like any other bust of Caesar to me. So probably not him.