Viking Voyager – Copenhagen, Stockholm & Oslo

A 13-night round trip from Southampton, sailing on the afternoon of 15 May. It calls at Copenhagen (until midnight), Helsinki, Tallinn, Stockholm, Visby, Oslo and Kristiansand, with five days at sea along the way. The stops are in Denmark, Finland, Estonia, Sweden and Norway, and calls last 9 to 10 hours. Typical highs for the time of year run from 14°C in Helsinki to 17°C in Oslo (57 to 63°F). You're back in Southampton at 6:30 AM on 28 May. Celebrity Apex (2020) carries up to 2,910 guests on 16 decks and has 14 restaurants, 8 of them included in the fare.