Can someone help identify this young adult book, I remember reading it about 10-12 years ago. Some teenagers go on a school trip to Whitby(?) and are staying in a hotel or something, and one of the rooms is occupied by a strange man. During the course of the book, they all acquire seemingly random items (the most memorable for me is a wooden kite which breaks).
At the end the items all become useful for defeating the strange man who turns out to be a vampire (the kite becomes a cross, maybe one had holy water, possibly garlic?)