Well, just like any company it is law to give an x number of days off per an x number of work days, plus when the ship docks they do give employees a few hours to scamper off and party in whatever country that is being visited. And it's not like you will be on the same cruise for all four months. Some cruises last one week, some one month, so there will be alot of variety which prevents you from getting bored of your job. But after all, wouldn't it feel like we are already on a holiday with a job like that anyway?