Belize Audubon Society from Green Living Project on Vimeo.
You can see a lot of St. Herman's Cave, including the tubing adventure there, and the Blue Hole National Park in this professionally done video from the Green Light Project. It also highlights Cockscomb Basin. The BAS manages those, and quite a few other parks around Belize.
"Since its formation in 1969 the Belize Audubon Society (BAS) has been Belize's foremost environmental organization protecting Belize's precious natural resources while educating the public about their value and sustainable use. BAS has grown from an all-volunteer organization with 55 charter members to a Society of over 1,400 members and a staff of more than 40 dedicated professionals."