not that I know of. Most insurance companies tend to offer much the same cover (and you may be able to claim against your household insurance), but you'd need to check the fine print. In particular, you'd probably want high coverage for possible hospitalisation, as it might have to cover an American hospital if anything went wrong in the Caribbean.
Did ours through insureandgo.co.uk, but if you go to someone else check that you are covered for cruises as not all companies tell you you are not...until it is too late!