| IMO | 9636888 |
|---|---|
| Gross tonnage | 133,019 GT |
| Length | 306.0 m |
| Beam | 37.2 m |
| Passenger capacity (max) | 4947 |
| Service speed | 22.5 knots |
| Builder | Fincantieri |
| Hull number | 6203 |
| Launched | 2013 |
| Maiden voyage | 2014 |
| Class | Dream-class cruise ship |
| Operator | Costa Cruises |
| Status | Active |
Overview
Costa Diadema is a Dream-class cruise ship operated by Costa Cruises (Costa Crociere), ordered in October 2012 and delivered on 25 October 2014. At delivery she was the largest vessel ever to fly the Italian flag and Costa's largest ship, and she remained the line's flagship until Costa Toscana replaced her in that role in 2022. Her name — Diadema, a diadem or crown — was chosen to present her as the jewel of the fleet, and Costa marketed her at launch as a showcase of Italian design, food and hospitality, built in Italy by Fincantieri for a reported US $739 million (€550 million in launch reporting).
Note on figures: the dataset and her article differ on tonnage in their headline forms, on launch year, and materially on speed. Those differences are set out in Key specifications and logged; the spec box retains the dataset values.
Key specifications
The dataset records Costa Diadema at 133,019 GT, 306.0 metres long, 37.2 metres in beam, maximum capacity 4,947 passengers, speed 25.5 knots, IMO 9636888, Fincantieri hull 6203, launched and in service in 2014, Dream class. Her article gives 132,500 GT in its infobox, the same 306-metre length and 37.20-metre beam, a draught of 8.35 metres, capacity of 3,724 passengers at double occupancy and 4,927 at maximum occupancy, and a crew of 1,253. Costa's own fleet table gives 133,019 GT — the dataset figure — which supports treating 133,019 GT as the line's figure and 132,500 GT as a rounded or earlier published figure. Maximum capacity likewise appears as 4,947 in the dataset and 4,927 in the article, a 20-passenger spread typical of cabin-configuration changes; neither is silently preferred here beyond the spec-box convention.
Dates also need care: the dataset's "launched 2014" is her delivery year. Her article records launch on 15 November 2013, completion 25 October 2014, acquisition 30 October 2014 and christening 7 November 2014. The narrative follows that chronology.
Design and construction
Diadema was built by Fincantieri at Marghera, Venice, in launch reporting of the delivery — the yard that built Carnival's Dream-class ships — as a modified Dream-class design for Costa. The Dream platform is a broad, high-capacity hull with a long promenade, extensive balcony accommodation and a central entertainment spine; Costa's version reworked the interiors and outdoor decks for the Italian market rather than changing the naval architecture.
Launch reporting recorded 1,862 staterooms and a build involving about 3,500 workers and 400 supplier companies, with Costa describing the ship as its 15th Fincantieri-built vessel and the yard describing her as its 44th cruise ship since 2002. Keel laying was on 10 December 2012 in one delivery account; float-out followed on 15 November 2013, and fitting out occupied the following eleven months to the October 2014 delivery.
Naming, launch and maiden voyage
The name Diadema was announced with the project as a crown-jewel statement for the fleet; Costa's launch presentation framed the ship as "the best of Italy" in lifestyle, hospitality and elegance. She was launched — floated out — on 15 November 2013. After completion on 25 October 2014 and formal acquisition on 30 October, she made a maiden voyage beginning 1 November 2014, was christened on 7 November 2014, and entered regular service on 8 November 2014, in her article's sequence. The dataset records only the year 2014 for both launch and maiden voyage; the precise sequence above is the corrected chronology and the launch-year difference is logged.
No godmother is named in the sources used for this guide, and none is asserted — a deliberate gap rather than an omission, since naming-party detail for this ship is not carried in her article summary.
Career by operator
One operator and one name for the whole career to date.
| Period | Name | Operator |
|---|---|---|
| 2014–present | Costa Diadema | Costa Cruises (Costa Crociere) |
Her career falls in the period in which Costa, after the loss of Costa Concordia in 2012 and the gradual retirement of older tonnage, rebuilt its fleet around a small number of very large ships: Diadema in 2014, then the LNG-fuelled Excellence-class pair in 2019 and 2021. She is the bridge ship in that story — the last of the conventionally fuelled, Dream-derived flagships before the LNG generation.
Onboard character
Costa presented Diadema at launch as a floating showcase of Italian style: Italian food and wine as the core offer, interiors organised around social, open spaces, and the long Deck 5 promenade as an Italian boulevard at sea. Launch descriptions emphasised that public areas were designed to feel more spacious and modern than on earlier Costa ships, with the promenade's six food and drink spaces and its outboard jacuzzis as the novelty. That positioning — a national showcase as much as a cruise product — is her era-defining character, and it distinguishes her from her Carnival Dream-class sisters, whose theming was American resort in character.
The multi-deck atrium, show theatre, spa, casino and pool decks follow the Dream-class arrangement in Costa form. Venue names and restaurant brands have changed with Costa's fleet programmes since 2014 and are not catalogued here; the promenade and the Italian-showcase concept are the durable design facts, both dating from delivery and both still legible in the ship's layout.
Major refits and incidents
No major casualty, fire, grounding or collision involving Costa Diadema is recorded in the sources used for this guide, and no major structural refit is recorded in her article summary. Her drydock history to date, in the sources available here, is routine maintenance rather than rebuilding. As with Celebrity Edge in this batch, this section is a sourced negative: the absence of an incident record in her article is stated as such, and nothing has been supplied to fill the space. A fuller refit chronology, if required, should be added only from a sourced ship-database record at a later update.
Context that does belong here is class context rather than ship incident: Diadema is a Dream-class ship in Costa service, not a Concordia-class ship, and the 2012 Concordia disaster is not part of her hull history. Directories frequently blur Costa's classes; this guide does not transfer a sister-line casualty into this ship's record.
Sister ships and class
The Dream class originated with Carnival Cruise Line's Carnival Dream (2009), Carnival Magic (2011) and Carnival Breeze (2012), all Fincantieri-built at about 130,000 GT. Costa Diadema (2014) is the Costa development of the same platform — described in Costa's fleet table as a modified Dream-class ship — and at 133,019 GT the largest of the group. She has no Costa sister built to the identical design; within Costa's fleet she sits between the modified Concordia-class ships Costa Favolosa and Costa Fascinosa that preceded her and the Excellence class that followed her.
For comparison within this batch, she and Costa Serena show Costa at two moments: Serena, a 2007 Concordia-class ship, and Diadema, the 2014 Dream-derived flagship — a larger, promenade-centred design that marks how Costa's product changed between those orders.
Fate and where she is now
Costa Diadema is in active service with Costa Cruises under her original name, IMO 9636888, status "Operating" in the dataset. No sale, charter out of the group, rename or retirement is recorded in the sources used. Her historical position is fixed as Costa's 2014 flagship and the largest Italian-flagged vessel of her delivery moment, whatever her future deployments may be.
Sources: https://en.wikipedia.org/wiki/List_of_cruise_ships, https://en.wikipedia.org/wiki/Costa_Diadema