Interesting question. You are allowed to be outside of the place where you are living in order to return home, but I take it that St Lucia is not your home, so as I read it, the exception for returning home would not technically allow you to go to St Lucia.
Are you going there for work, or to fulfil a legal obligation, or to visit a friend or family member in hospital / death bed / jail, or for a wedding / funeral / childcare, or to view / manage residential property, or because you are going to make St Lucia your home? Those are valid reasons to be outside the place where you are living.