Must admit we ran up a bill of £40 for water from our minibar. The cruiseline are rightly concerned about people filling up their water bottles from dispensers because of the spread of germs but you can always take half a dozen glasses of water and fill up your bottle where spillages will not cause slips. Although probably safe to drink I never like tap water from the ships .
There is free tea, coffee, water and old-fashioned type lemonade available all day. Yes, it is perfectly safe to drink the tap water too.