Jimi was pretty exhausted in his 1970 Isle of Wight performance, and this All Along the Watchtower version wasn't necessarily a high point in the show.
However, I'm posting this for the alternative way in which he plays the studio version's slide section in a live context without slide. I'm referring to the section immediately preceding the wah wah section.
Note that Hendrix is tuned 1/2 step down to Eb, making the tune's opening chord a B, which would geographically be located where "A " is when tuned in standard pitch. Unless you tune down to Eb, I recommend playing this in A in order to get the right chord voicings, drones, etc. Although you also might tune down just to learn it, then shift back to A afterwards.
Anyway, I've always wondered what to do in that section-- and this video is helping me work that out. Maybe this will help you too!