[jiggyboy]

Another reason to film the interior would be to work out where good hiding places are. Smuggling comes to mind.

[GretchenEE]

Re smuggling - these are ferries that leave Washington docks and travel across Washington waters to other Washington docks. No need to smuggle across the water when most of the destinations can be reached by driving (islands excepted). Of course, if terrorists' main goal is to get near our numerous military installations at water's edge, that creates a different concern, since entrance to military stations is so restricted.