A cruise ship theatre show takes up to two years to make. That is one of the revelations from NCL's head of entertainment Bryan White, who has lifted the lid on how Norwegian Cruise Line picks and produces the headline shows aboard its ships.

White describes the selection process as part data science, part creative judgement. NCL studies demographic data, cruise lengths and regional routes to work out who is actually on board, then asks whether a concept delivers the scale and quality of a night out in London or New York. Vegas residencies and big concerts are the key influences — the aim is a spectacle guests talk about for years.

The timeline is longer than most people would guess: 18 to 24 months from first concept to opening night. Ideas go through repeated internal reviews, then a workshop phase to develop the story, followed by casting, set design and build. Four months before installation, the cast moves into NCL's rehearsal studio in Tampa, Florida for costume fittings and rehearsals while the technical team works on lighting, sound and video. There are dress rehearsals, rounds of notes, and even preview performances for crew before paying guests see it.

Keeping different generations happy is the core challenge. White says shows need a universal hook, cutting-edge theatre tech, live instrumentation — and tight pacing, because cruise guests want high impact without committing their whole evening. Headline productions typically run twice a night over several days so everyone gets a seat, with alternatives like rock sessions at Syd Norman's, comedy sets and late-night cabaret elsewhere on the ship.

Shows live or die by guest feedback. NCL tracks post-cruise surveys, audience ratings and attendance every week, and will extend a hit, rework a storyline, or quietly retire a show that has run its course. The Elton John-focused production on Norwegian Aqua has clearly passed the test — White calls the response impressive.

The next big bet is a Whitney Houston tribute headlining Norwegian Aura, the line's newest and largest ship, launching next year. Developed with The Estate of Whitney E. Houston and Primary Wave Music, it will be a 45-minute theatrical concert with a live band in a three-storey theatre. Crucially, White stresses it is not an impersonation act: there will be no single performer playing Whitney, but a contemporary staging of her catalogue — think 'I Will Always Love You' and 'I Wanna Dance with Somebody'. He has already seen the workshops and says simply: they have a great show.

For anyone weighing up which cruise line to book, this matters more than it might sound. Entertainment is now a genuine differentiator at sea, and NCL's strategy — pop-music headline shows with official artist estates, plus bars and lounges with their own smaller acts — is designed to rival a land-based theatre trip. If you are the kind of traveller who books a musical when visiting a big city, the on-board schedule may now genuinely factor into which ship and sailing date you choose.