There is a persistent myth that cruises are always cheapest at the last minute. Sometimes they are. But the thing people actually regret is never the fare — it’s the cabin they couldn’t get, the excursion that sold out, and the flights that doubled while they waited.
The short version
Book early when your dates are fixed, your party is large, or you care where you sleep. Wait only when you are genuinely flexible about everything — destination, week, and cabin — and you can leave on short notice.
What sells out, and when
Inventory does not empty evenly. The categories that disappear first are the ones with the fewest rooms: connecting cabins, accessible cabins, aft-facing balconies, and anything in a suite tier. On a popular summer sailing those can be gone the better part of a year out, while ordinary interiors still sit available the week before departure. That is why a “last-minute deal” so often means an interior cabin on a deck you would not have chosen.
Shore excursions follow the same rule with less warning. The capacity-limited signatures — glacier flights, a railway with a fixed number of seats, timed entry at a famous site, anything involving a small boat — routinely sell out one to three months before sailing. Those cannot be recovered later at any price.
Where waiting genuinely pays
Flexibility is the only real lever. If you can sail in the quiet weeks between school holidays, take whatever cabin is left, and book inside a couple of months, you will see softer pricing. Repositioning sailings — the ones that move a ship between regions at the turn of a season — reward the same flexibility, because they end somewhere other than where they started and fewer people can make the dates work.
The part nobody budgets for
Airfare moves against you while you wait. A fare that drops a little and a flight that climbs a lot is a net loss, and it is the most common way a patient booking ends up costing more. If you need to fly, price the whole trip together or you are optimizing the smaller number.
What we’d tell a friend
Pick your week first and your ship second. Book when you find a cabin you’ll be happy in, lock the excursions that have hard capacity, and stop watching the price — most lines will honor a better rate or an improved offer if one appears before final payment, and your specialist watches for that so you don’t have to. That is the whole trick: you get the cabin you wanted and still get the upside.