What is a cruising duck, and why is there one in your cabin?

If you have found a small rubber duck tucked behind a handrail, on a deck chair or beside the library shelf, you have not found lost property. Someone left it there on purpose, for a stranger, and that stranger is you.

Where it started

The practice is usually traced to a family sailing Carnival in 2018 who hid a handful of numbered ducks around the ship with tags asking finders to post a photo. It spread the way things spread on cruise ships — by people talking at dinner — and within a couple of seasons it was running on most major lines.

The rules, such as they are

There is no organisation behind it and no official rulebook. What has settled into convention is simple: if you find a duck, it is yours. You can take it home, or you can hide it again somewhere new and let it keep sailing. Roughly half of finders do each.

The etiquette nobody prints on the tag

Keep ducks in public indoor spaces where they cannot fall, block anything, or be mistaken for something left behind. Never on railings facing open water — a duck in the sea is litter, not a game. Never at a muster station or lifeboat, and never in crew-only areas. If a crew member asks you to move one, move it without argument.

Why the numbers matter

Numbered ducks let you see where yours has been. Ours carry a six-digit number and a QR code, so a finder can log the ship, the deck and the next port — and the duck accumulates a travel history that outlives any one passenger.