Could Jose Salvador Alvarenga really have survived 13 months or so floating at sea?

[youtube http://www.youtube.com/watch?v=K5SRlrtYuSg&w=600&h=315]

I used to read all those Alive books as a kid, because I thought there was a chance I'd be in an avalanche (I've never been skiing, in all honesty) or have to save my family from a fire (a small kitchen one, perhaps) or would need to figure out how best to survive on turtle urine while stra…