Stumped? Highlight for answers:
1. P&O Cruises (P&O Ventura‘s smokestack),
2. MSC Cruises (MSC Splendida‘s top deck),
3. Holland America Line (ms Nieuw Amsterdam‘s aerial view),
4. Norwegian Cruise Line (Norwegian Escape‘s bridge and upper decks),
5. Windstar Cruises (Star Breeze‘s bow).
Unless credited otherwise, photos courtesy of their respective cruise lines.