Thanks for the link, that's cool to see what has changed and what has stayed the same in the last 100 years. Even back then the Pagan river channel was narrow and crooked!
Jamestown Island is as far up the river as we have ever ventured, so I don't have any first hand information beyond that. I would like to make the trip all the way up to Richmond one of these days, but Chippokes is a favorite with my kids, so we usually don't get beyond that.
One other thing I should have mentioned in the earlier post is that being wide and fairly shallow, it doesn't take much wind to kick up a nasty chop on the James. I think the river narrows down past Jamestown, so it might not be as big of an issue up there.