Oxcamp1,
AS you can imaging, it's low and getting lower. Also, this time of year the river usually blows out late morning to early afternoon due to glacial melt. Visibility can easily go to less than a foot and that makes it very difficult to see rocks. You can really bang the hell out of your boat if you don't know exactly where to go. So if you're not familiar enough with the river to know where the deeper slots are, I'd advise you do a quick morning float rather than an all day one, especially if you're in a drift boat.