Symphony of the Seas measures 361.011 metres (1,184 ft 5.0 in) in length and has a gross tonnage of 228,081 across 18 decks. She is able to accommodate 5,518 passengers at double occupancy up to a maximum capacity of 6,680 passengers, as well as a 2,200-person crew. There are 16 decks for guest use, 22 restaurants, 4 pools and 2,759 cabins. Symphony of the Seas is about 30 metres (98 feet) longer than the largest military ships ever built, the U.S. Nimitz-class aircraft carriers. Facilities include a children’s water park, a full-size basketball court, an ice-skating rink, a zip line that is 10 decks high, a 1400-seat theater, an outdoor aquatic theater with Olympic-height platforms, and two 43-foot (13 m) rock-climbing walls. There is also a park containing over 20,000 tropical plants.
The energy-efficient design of Symphony of the Seas enables it to accomplish shipboard power generation with 85 MW versus the 100 MW normally found on Oasis class ships. One of the key design features is the use of only LED or fluorescent lights in order to avoid the heat generation from incandescent bulbs, thereby reducing the load on air conditioning systems. Additional energy efficiency is accomplished by using a 2 MW steam turbine to recover waste heat from the engines and converting it into energy to power a portion of the onboard hotel load. For propulsion, Symphony of the Seas uses three 20,000 kilowatt azipod main engines, which are electric thrusters. These engines are mounted under the stern of the ship and they each drive 20 foot wide rotatable propellers. In addition to the three main engines, there are four bow thrusters used for docking, each with 5,500 kilowatts of power or 7,380 horsepower. Among the Oasis-class ships, Symphony of the Seas uses 25% less fuel due to the implementation of a new system that releases tiny air bubbles under the hull to enable the vessel to glide more smoothly through the water. The air layer also reduces excitation from the propellers, which cuts noise and vibration levels in the aft part of the ship.
On 31 March 2018 Symphony of the Seas offered her first passenger cruise and began her maiden voyage on 7 April for a week-long trip through the Mediterranean. During her first season Symphony of the Seas continued to sail on seven-night Western Mediterranean cruises from Barcelona. She repositioned on 28 October and arrived on 9 November at her new home port at the Royal Caribbean terminal at PortMiami in Florida, United States to provide cruises of the Caribbean. Homeport is Nassau, Bahamas.
