Sunrise on Running Water — Barbara Hambly

A vampire novelette of 9,000 words. The evil vampire Lord Napier Sandridge seeks to flee the vengeful sister of his most recent victim. He chooses to travel to America aboard the safest and most luxurious vessel he can find: the RMS Titanic. Since vampires lose their powers on running water, he feels that an "unsinkable" craft is safe. The ship loads in twilight, and even when the ship strikes an iceberg, he reasons that rescue must come before dawn breaks and the sunlight ignites him in unquenchable flames... What could possibly go wrong?