With the cruise industry booming, cruise operators are actively pursuing newer and larger ships to cater for demand. Combining increasingly larger capacities with luxury can often prove to be a daunting, but ultimately profitable endeavour.

Although Royal Caribbean International possess the majority of the world's largest cruise vessels, ships such as the Queen Mary 2 and appropriately named Norwegian Epic post valiant attempts to enter the list.

The largest cruise vessel in the world with a maximum capacity of 6,400, Allure of the Seas has been operated by Royal Caribbean International since 2011.

Delivered in October 2010, it is the sister ship of Oasis of the Seas and was constructed with at a cost of $1.2bn. Her maiden voyage was a tour of the east and west Caribbean that started in December 2010.

The ship contains 2,704 double-occupancy staterooms and loft suites across 16 decks.

Oasis of the Seas is the first of the Oasis Class luxury cruise ships operated by Royal Caribbean International, having been ordered in February 2006.

The keel was laid in December 2007, and the ship entered service two years later in December 2009.

The estimated cost of the vessel was $1.24bn and she is the second largest operational ship, with a maximum capacity of just 104 fewer passengers than that of her sister ship, Allure of the Seas.

Norwegian Epic is the world's third largest cruise vessel and Norwegian Cruise Line's largest and most innovative ship, including a wide array of amenities entertainment venues and dining facilities.

The 1,081ft-long vessel as a gross tonnage of 155,873 and a maximum capacity of 5,183, spread across 2,114 staterooms.

Norwegian Epic was delivered on 17 June 2010, and its cruise itinerary includes seven-night Western Mediterranean sailings.

Ordered in September 2003, Freedom of the Seas is the first of three Freedom-Class vessels commissioned by Royal Caribbean International. She was once the world's largest cruise ship, having since been overtaken by Allure of the Seas.

Constructed at Aker Finnyards' Turku Shipyard at a cost of $800m, the vessel's homeport is Miami and made her maiden voyage to the Caribbean in June 2006.

The ship has the capacity to host 3,634 passengers alongside a crew of 1,360, with 15 of the 18 decks reserved for passengers.

Independence of the Seas is the second Freedom-class vessel of the Royal Caribbean International fleet, becoming the sister ship to Freedom of the Seas and Liberty of the Seas.

Constructed at a cost of $590m, she was officially named at a ceremony in Southampton on 26 April 2008. Her maiden voyage was a four-night cruise to Cork on 2 May 2008, followed by an 11-night cruise to the Canary Islands on 6 May 2008. All three Freedom-class vessels have a gross tonnage of 154,407GT, and a maximum capacity of 4,375.

At the time of her construction at the Chantier de l'Atlantique yard in 2003, the Queen Mary 2 cruise ship was the largest ocean liner ever constructed.

The registered Gross Tonnage is 150,00t, and the vessel has a maximum capacity of 3,090. She embarked on her maiden voyage from Southampton to Fort Lauderdale, Florida, in January 2004. Four Wärtsilä diesel engines, supplemented by two gas turbines, propel the ship with a total output of 118MW.

The third ship of the Fantasia Class series, MSC Divina is owned and operated by Mediterranean Shipping Company subsidiary MSC Cruises. Having been introduced in May 2012, Divina is the newest and largest ship in the class, sistering both MSC Fantasia and MSC Splendida.

She embarked on her maiden voyage on 27 May 2012, having been officially baptised by Oscar-winning actress Sophia Loren on the previous day. The ship's interior areas were designed and outfitted by De Jorio Design International.

Navigator of the Seas has the capacity to house 3,807 passengers across 1,557 staterooms, with almost 50% of those having balconies.

A crew of 1,213 are housed within 290 crew cabins. Having been constructed at Aker Finnyards in Finland for Royal Carribbean International, the ship contains more than $3m of art work displayed in stairwells and public areas.

She is the fourth of five Voyager-Class cruise vessels operated by Royal Caribbean International.

Another of Royal Caribbean International's Voyager-Class cruise ships, Explorer of the Seas completed on 28 September 2000.

The vessel can accommodate more than 3,100 guests, and possesses a unique feature of a built-in atmospheric and oceanographic laboratory which aid the National hurricane Center by providing meteorlogical data. With a gross tonnage of 138,000 and a total length of 1,020ft, Explorer of the Seas has a cruising speed of 23.7kt.