1) People who stop on the gang plank while boarding to take photos of each other ... one quick snap - no problem - but when they block the walkway for group shots, are digging in their bag for cameras, I want to scream. Step to the side folks!
2) The Know-it-All Cruiser who feels it is their duty to tell people what to do or not do. They run around the ship offering unsolicited advice and 90% of the time are wrong. Don't give advice unless asked!
3) The Irritable and Rude - For once in your life, try to be pleasant and not complain. Breathe, relax and enjoy - stop looking for things that are wrong and inflicting your negativity on everyone around you.