Two stories from Noonsite, and the has been a discussion on Cruisers_Network_Online about the Isla Mujeres story.
The PNG attack was the first yacht attack reported to Noonsite since January 2008, and characterized by the use of knives and machetes and 6 men.
The Isla Mujeres story tells of s cruisers experience bringing in (and declaring) a pistol and ammunition to the authorities. It turned out well, but could have been much worse. Noonsite also has a page covering the entry process for yachts here.