Most of our cruises have been during xmas holidays in Dec-Jan..............we are pleasantly surprised and delighted when we have beautiful warm sunny days......there will typically be a very windy day at sea when a windbreaker or long sleeved tshirt will be perfect; there will also be a rainy day, perhaps even a downpour--again, the hooded windbreaker is great......also, you will be indoors onboard and it is air-conditionned, so a light wrap, sweater, suit jacket is good for dinner and showtimes...........i usually layer with the tshirt topped off by a long sleeve cotton shirt or jean type jacket (in bright caribbean colors of course!) since we fly from up north, i usually wear a cotton hoodie-type sweater and jean type jacket on plane with long pants and that is my cool weather outfit! i also like a velour type lounge suit for mornings, verandah and breakfast...........