Regent Seven Seas, Explora Journeys, Silversea, and Seabourn are all owned by different cruise giants. Here's how some of their ships compare in dining, amenity, and cabin options.Brittany Chang/Business Insider, Explora JourneysCruise giants Royal Caribbean, Carnival, Norwegian, and MSC each own ultra-luxury cruise lines.I've been on their brands' Silversea, Seabourn, Regent Seven Seas, and Explora's ships.Here's how they compare in amenities, food, cabins, and 2025 itineraries.Almost every cruise ship has a pool, buffet, and casino.Only a few flex complimentary caviar and $600-a-day prices.Industry giants Royal Caribbean, Norwegian, Carnival, and MSC flaunt giant amusement park-like ships.