Do i qualify for a UK ancestry visa?

I'm planning to move to London sometime around 2012 and I'm trying to soak in as much knowledge & advice in so that it'll be easier for me to move there for Uni. Researching upon making a such big decision in my life, that there IS a such thing as an ancestry visa. I'm of mixed race. My grandfather (now deceased) is of black west indies ancestry (british), BUT he wasn't born directly in the Turks & Caicos. His parents were. He was born in another island in the Caribbean. So, I was wondering do I still have a chance in getting the visa or nay?