Costa Diadema is a Dream-class cruise ship operated by Costa Crociere. The ship was ordered in October 2012 and was delivered to Costa on October 25, 2014. Costa Diadema is the largest vessel flying an Italian flag and currently Costa Crociere's flagship. It was launched on 15 November 2013 by her madrina (godmother) Franca Grasso, a member of CostaClub chosen from among more than 12,000 guests who sailed on Costa ships in the Mediterranean during October and November 2013.
Costa Diadema's embarkation area, Eliodoro Atrium, is also a popular meeting spot. It features an installation spanning multiple decks. On deck 5 of the vessel is a 500 m (1,600 ft) promenade, the longest in Costa’s fleet. Costa Diadema also has three swimming pools, one of which is covered by a retractable roof and also functions as a party space.
There are three large dining rooms in different flors - Fiorentino, Adularia and Corona Blu, the last of which transforms into a buffet by day for breakfast, lunch and brunch. All three of these dining rooms are mainly focused on Italian cuisine from different regions with lot of fruit and sweets (breakfast, brunch) and less different drinks - except for suppers. At an additional charge, passengers can choose to dine at the “à la carte” Club Restaurant, Samsara Restaurant, or Tavola Teppanyaki or order pizza, which offers griddle-prepared Japanese food.
Costa Diadema has a total of 1,862 staterooms in 14 different categories, including inside cabins, balcony cabins and suites. The 130 staterooms and 11 suites on Decks 11 and 12 may be combined with a package giving special access to the four-level, 6,200 m2 (67,000 sq ft) Samsara Spa, Costa's largest wellness and beauty area. Staterooms are equipped with flat-screen televisions, and (at an additional charge) Wi-Fi and room service are also available. Passengers occupying suites have access to priority boarding, a choice of pillow from the Pillow Menu, a Jacuzzi, and (if the suite is full sized) a personal butler. Number of staff i lower than on some other luxurious ships.
As of 2015, the vessel’s three-level Emerald Theater was presenting four live productions, and another show was expected to be added the following year. Country Rock Club had a live band playing classic tunes, and nearby was Birreria Dresden Green, a German-themed beer garden. The Star Laser area had facilities for gamers, and a laser maze. Small casino is very frequented during the night as some duty-free shops. There was also a 4-D cinema (payable) showing a number of five-minute movies and a Grand Prix motor racing simulator. Late night entertainment was provided by a small piano bar and a discothèque.
The Costa Diadema has 19 decks, 14 of them are for public use: