aboard ship, the usual fashionable cruise attire, shore excursions think
Cold as H-ll maybe, better to be warm and snuggly than be miserable.
as for shipboard dress, same as any cruiseship.
look your best, act as if you belong and then have one hell of a goodtime.
this is not like relatives, the odds are you will never see the same
But for G-d's sake don't dress as if was a refuge boat.