For every weakness a Vampire has, they also have a strength.

Among these is the ability to breathe underwater, since they do not need to breathe at all on account of being undead.

Most undead also recognize a Vampire's power, and as such tend not to try and harm them.
This doesn't apply to all creatures of the night, however.

More powerful Vampires can also turn into a Bat.
This ability is more closely examined in its dedicated chapter¹.

Vampires also have night vision, though not quite as strong as the potion.
This is especially useful in caves, where the darkness often hides valuable ores.

1 → {The Bat Form|sanguis:vampires/strengths/the_bat_form}