I was there last year and couldn't find anything that was completely up to date but the information in the 2nd edition (2009) of the Stephen J. Pavlidis guide was mostly accurate. edit: I should point out that is A Cruising Guide to Puerto Rico
, not the relevant section in any other Pavlidis guide.
There is also a free cruising guide which is a little self serving and you have to wade through the advertising but is also worth a read. Hey, it's free!
Puerto Rico Cruising Guide » PUERTO RICO CRUISING GUIDE