Minnevan Cruiser

If I may piggy back on this question, If you put cash down so long as your account not over you walk off the ship with the remaining cash back? Is it in the form of a check or cash? I ask because we have prepaid gratuities and have a drink package so we are really not planning on incurring more expenses on the ship. If I put down the full amount asked I expect to get a heft bit back at the end of the trip. I don't have a credit card for personal reasons.