RCI does not have ships sailing from Southampton during the winter months. RCI does not do sailings to the Caribbean - apart from the Transatlantic repos at the end of the seaso.
You put down RCI as your preferred line and as "A of N" says they do not offer this in winter from Southampton but there are plenty of other companies which do. Cunard, P & O, and Fred Olsen to name but a few. I suggest that you pop into a travel agent in Camelford or Wadebridge or Launceston and if that's not practicable ring them and ask for them to be posted to you, pick out what you like then check out the prices they have and on the net and for that matter on this site and enjoy a warmer winter away from the slate .... don't do dreckly do now cheers ....Nei.
There are no ships sailing from Southampton in Feb as they are all either on World Cruises or in the Carribean. If you specifically want to go to the Carribean in Feb, then the only way is to fly. If you want to sail round trip then you can do it in Dec or April and other months between April & Dec.