We did St. Thomas to Culebra, Puerto del Rey, Vieques and back last October. It was a great trip with excellent fishing between St. Thomas and Culebra. It was 3-4 hours there and a bit longer coming back. We loved and will try and fit in another visit as soon as possible.

Printed guidebooks are pretty outdated. I found the free cruising guide from Frank Virginitino usefu - http://freecruisingguides.com/free-cruising-guides/puerto-rico/

Here's a post about the trip:

https://dinghylife.wordpress.com/2015/11/23/culebra-4-nights-october-19-22-2015/

Cheers, RickG