Swimming from Alcatraz? FFS, get a grip! I've been to SF a couple of times and although the currents look quite strong it's not much of a distance as you can see the land from the island and they even wear wet suits!
You should try a real challenge like our national custom - swim the English channel between England and France. It's 26 miles and so far over the horizon that you can't actually see where you're going. No wet suits allowed, just cover yourself in lard and hope for the best.http://www.channelswimmingassociation.com/
I'd rather die peacefully in my sleep like my Grandfather,
than screaming in terror like his passengers.- Jim Harkinshttp://www.Horrible.Demon.co.uk/