I have been to Alaska a few times and fished with the bears...a lot of bears. After the initial adjustment of them being very close, and me understanding to give them their space, it really never bothered me or made me that nervous. Well there was one incident , but that is a long story and I learned to always keep my brother between me and a bear. You quickly realize they can move very fast and they appear out of nowhere. In addition, the area I was in they see a lot of fisherman.
I am planning on a trip this summer where there are bears that don't really see a lot of fishermen. This has me thinking. I don't think bear spray would have phased this dude. Should be fun!