Oldvarnish, I know of no dedicated blogs, but you can check out:
Cruising to Calm
This is a blog called 'Cruising to Calm' and they spent considerable time in the area (from October 2008 to January 2009) and have many entries covering the islands off the coast of
Venezuela as well as
Columbia. In addition, you can always check out:
www.noonsite.com/
Numerous entries on
security in the area are available.
Finally, Chris Doyle now has a cruising guide to
Venezuela, as well as the island off the coast.
Cheers!
Brad
you can check out
www.noonsite