In part 1, we followed Lucía as she booked her cruise. Now she’s on board.
It’s 11 p.m. and the ship is hundreds of miles from the nearest coast. In the casino, someone charges a bet to their account. In the restaurant, a server sends an order from a tablet. At reception, a passenger changes tomorrow’s excursion. On the bridge, dozens of sensors report on engine status, fuel consumption and weather conditions. And in a cabin, a little girl is on a video call with her grandparents.
All of this runs on something no passenger ever sees: one or more data centers installed inside the ship itself.
A modern cruise ship is, for all practical purposes, a small floating city. Royal Caribbean’s Wonder of the Seas can carry nearly 7,000 people, and all of them expect to stay connected during the voyage. But unlike a city, the ship can’t rely on the power grid, fiber optics or a nearby data center. It has to carry everything it needs.
The list of systems that depend on this infrastructure is long. Cabin door access and access control. Onboard payments, which on many ships are charged to a single account linked to each passenger. Reservations for restaurants, shows and excursions. Internal crew telephony and the Wi-Fi network. Security cameras. Digital signage, which shows real-time availability at restaurants and activities. And the ship’s own technical systems: according to consultancy Marine Digital, a modern ship generates more than 20 GB of data a day from sensors that track engines, fuel consumption, speed, temperature and external conditions.
Why not move all of that to the cloud? Because at sea, connectivity is a scarce resource. For years, ships relied on expensive, limited satellite links. Bandwidth management became so critical that Royal Caribbean configured its systems so that emails between crew members on the same ship never left it, instead of making a round trip through its Miami headquarters. Costa Cruises, for its part, opted for infrastructure that was as self-sufficient as possible, with an IT manager on board who coordinates with the shore team.
Connectivity has improved a great deal. Royal Caribbean was the first cruise line to deploy Starlink across its entire fleet, with installation scheduled for completion in early 2023. Each maritime terminal delivers up to 350 Mbps. But better connectivity hasn’t eliminated onboard data centers. It has changed their role.
The model taking hold is hybrid. AROYA Cruises, for example, operates three data centers aboard its flagship, with its applications replicated to the cloud in real time. If the satellite link goes down, the ship keeps running. If the ship has a problem, the data is safe on shore.
Redundancy is designed as it would be for any critical infrastructure, with a twist that is unique to the sea. Royal Caribbean installed two data centers on its Oasis-class ships, with a backup center for critical applications that must survive an emergency. The are located in separate zones, so a single fire can't affect both at once. Icon of the Seas, one of the largest cruise ships in the world, has two data centers and around 40 IT distribution points spread across the ship. According to Rittal, the manufacturer that equipped them, everything runs on that infrastructure, from Wi-Fi to reservation systems, and there is no room for failure.
On board, however, space is worth its weight in gold. Every square meter dedicated to technology is a square meter not used for cabins, restaurants or shops, which are what generate revenue. On the Norwegian Joy, built by German shipyard Meyer Werft, the solution was to distribute IT across 21 technical rooms, each with three racks and two air-to-water heat exchangers. The chilled water comes from the ship’s own cooling plant. And spare capacity was left in case the vessel changed routes or passenger profile in the future.
That spare capacity is no minor detail. An onboard data center has a lifespan of around five to seven years, while a ship sails for decades. This means the IT infrastructure will be renewed several times over the life of the vessel, almost always without being able to stop operations. Costa Cruises renewed the data centers on seven of its ships without interrupting activity on board.
Then there’s power. On land, a data center connects to the grid and has backup generators. On a cruise ship, the power plant is the ship itself. The power that servers consume and the cooling they need compete with propulsion, air conditioning for thousands of cabins, kitchens and pools. Every kilowatt counts, and there’s no way to get more power in the middle of the ocean.
On top of all this comes isolation. If equipment fails on land, a technician can arrive within an hour with the replacement part. At sea, the next port may be days away. The onboard team is small and can’t have specialists in everything. That’s why components must be durable, critical spare parts have to travel with the ship, and the shore team needs remote visibility into what’s happening inside each technical room.
Seen this way, a cruise ship’s data center is an extreme case of something increasingly common on land: edge infrastructure, far from the large data center and with limited resources. Scarce space, finite power, tight cooling, few staff and no room for improvisation. In that environment, knowing in real time how much power each rack consumes, how the temperature in each room is evolving and how much capacity is left for the next refresh isn’t an advantage. It’s the only way to operate safely.
And the pressure isn’t going to ease. Every new digital service for passengers, from the app that unlocks the cabin to AI-powered personalization systems, adds load to an infrastructure that can’t grow in square meters.
The next time you see a cruise ship docked in port, remember that it doesn’t just carry thousands of people. It also carries a data center that has to run nonstop, on the move and hundreds of miles from any help.