Cheapskate. If these ships were registered in countries with labor laws, fair pay and compensation tipping would still say "thanks for wiping my ass, nose, toilet etc.)
While notorious superior acting guests, many who've never served the public, avoid tipping, realize, your cruise indentured, 3rd world servants work 7 days a week 10 to12 hours a day. If they get a couple hours on shore, they head right for the nearest Costco to buy soap, hygiene products and call home to their spouses, children and others at home.
Study up on cruise practices, international travel, how to avoid the UGLY LOUD BLOATED US Citizen stereotype. Where else can you eat your weight in bacon, do everything in excess, because you earned It!