..just a word of caution even if you have no other cover - for heavens sake do not leave home without a medical cover including Medivac from a ship!!!
Due to liability reasons every ships doctor is going to get you off his ship as soon as possible if you have anything more serious than a minor cut. Medivac in the caribbean currently costs anything between 15 - 25.000,- USD.
The Carnival Conquest however does not have a Helipad so they have to divert a whole ship and guess what - YOU pay for the additional fuel - oh and she uses 70 Gallons a mile!!!