Maybe if you're an evil vampire vegetable, you're happy to go out in the act of bludgeoning someone to death.
Madness string 1190
If vampires don't need air, they would be awesome scuba divers. They could just wear a backpack full of rocks and walk on the bottom. And if they dive deep enough, light won't even reach down there. Like, aquatic vampire covens at the bottom of ocean trenches...