Everyone in the New Zealand cruise debate quotes a big future number. Cruisey did something no one else has published: we built the 2036/37 cruise calendar as an actual port-by-port, month-by-month allocation, and tested whether 4,000 annual port visits physically fits New Zealand's ports. On today's berths, it doesn't — the network caps at about 3,351. Build every consented berth and flatten the season, and it reaches 3,935, still short. That is not an argument against ambition. It is what turns a number into a plan.
This is a companion to Cruisey's Theoretical 2036/37 Cruise Calendar, where the full model and dataset are published.
What the model actually does
A target of "more than 4,000 port visits by 2036" is easy to publish and hard to defend, because the obvious question — where exactly would those ships go, and on what day — has no answer unless someone does the allocation. So we did it.
The model takes nineteen New Zealand ports, each with its published berth count and maximum vessel length, and allocates visits across twelve months against a proposed seasonal shape. It then applies a hard physical check: the number of cruise calls in a month cannot exceed the number of berths multiplied by the days in that month. One "port visit" means one cruise vessel at one New Zealand port on one calendar day.
Where it breaks
On current berths, the network absorbs about 3,351 port visits before it runs out of physical capacity — and it runs out in a very specific place. To reach even that number, Tauranga would need a cruise ship every single day for six consecutive months on its one berth. Auckland, Lyttelton and the Bay of Islands each hit continuous occupancy for four months of the peak.
Flattening the season — the change most often proposed — adds barely 3.5% on its own, because spreading the peak just moves the problem to the shoulder months at the same single-berth ports. You cannot flatten your way past a berth count of one. Building every consented berth and flattening the season together reaches 3,935. That is 98% of the target, and still under it.
The real finding: New Zealand's cruise constraint is not demand, deployment or even cost. In a high-volume future it is berths at four specific ports in four specific months — a capital-works problem with a lead time measured in years.
Why nobody else has this number
The New Zealand Cruise Association and Tourism Auckland have both published cruise plans, and both are worth having. Neither has published a capacity model that stress-tests the national target against actual berths. That is not a criticism — it is the gap Cruisey set out to fill.
The distinction matters. A target you have not modelled is a number. A target you have modelled, with the constraints named and the dataset open for anyone to challenge, is a plan. It tells you what to build (Bledisloe North, a second Tauranga berth, cruise access at Lyttelton's Te Awaparahi Bay), in what order, and by when.
The winning move: publish the model, not just the target
Cruisey published the model's assumptions and its full dataset so that any port, cruise line or official can pull it apart. Some of the assumptions are ours and are arguable — we say which, and we would rather be corrected now than after the target is quoted in a select committee.
That is the concept that wins: not the biggest number, but the one you can defend down to the berth. The 4,000 ambition still stands — now with a condition attached, which is exactly what a credible target should have.
Source: Cruisey's 2036/37 cruise calendar model, published with its full dataset. Berth counts and vessel-length limits are published port operating limits; destination-capacity ceilings are stated Cruisey assumptions. Consented infrastructure — Bledisloe North Wharf, Tauranga's Stella Passage, Lyttelton's Te Awaparahi Bay — is drawn from the projects' own consent records. Everything in the model is a scenario, not a forecast.