If you're a member of the SSCA, check out the October 2016 Commodore's Bulletin article starting on page 16 - "A Northern Caribbean Cruising Triangle: Puerto Rico and the Virgin Islands." Lots of good detail and a good travelogue. The bulletin is behind a paywall.
https://www.ssca.org/dashboard/#/dashboard/bulletins/If you're a member of the cruiser facebook groups Culebra Cruisers and Boaters / Vieques Cruisers and Boaters you'll recognize Sue Klumb's name from the article. Sue is the admin for the facebook groups and a SSCA host. These facebook groups are a great resource for current info.
The article mentions the free Puerto Rico Cruising Guide written by Frank Virgintino available at Free Cruising Guides. This was the best single resource we had for last years PR/SVI cruise and it has been updated.
http://freecruisingguides.com/free-cruising-guides/puerto-rico/Cheers, RickG