Stop running games.

If your players are lazy bums, join some real-time online games via Roll20 or Google+.

Taking some time off might be just the thing. Gain a fresh perspective on how other people run games.

Figure out what the PCs depend on, value, or require.

Then threaten those things.

Let's say that one of the players is a college professor, using his TAs as a blood supply.

"Gangrel are gathering in the woods outside of town!" is a crap impetus to do anything.  Why does he care?  (Sure, he could *invent* a reason to care, but...)

"Gangrel are gathering in the woods in the university grounds!" is a better reason to care.

"Gangrel are in the woods in the university grounds, and are starting to snack on your food supply!" is as pretty good reason to care.

Even if the professor doesn't care about that particular food supply, if they are diminished/removed he has to find food *somewhere else*, which at least puts him in motion.

Alternately:

Discuss with your players out-of-character what kind of game they want to play in.  Not like the whole plot, but like the back-cover teaser it were a book, or maybe the trailer for a movie.  Then tell them "give me a reason why you'd care about ".  Then do to get them started.

Well, there is no need to merge the multiple threads, as, inexplicably, things went very well at the last game. I've been taking everyone's advice. I did not complicate the boat transaction.