6.Property and Equipment, Net

Property and equipment, net increased $1.5 billion for the nine months ended September 30, 2023 primarily due to the delivery of Norwegian Viva, a Prima Class Ship, and Oceania Cruises’ Vista, an Allura Class Ship. We determine the weighted average useful lives of each class of ships based primarily on our estimates of the useful lives of the ships’ major component systems on the date of acquisition, such as cabins, main diesels, main electric, superstructure and hull, and their related proportional weighting to the ship as a whole. We have assessed the weighted-average useful life of the components of Oceania Cruises’ Vista and assigned a useful life of 35 years and residual value of 10% to the Allura Class Ships. The useful life and residual value consider the historical useful lives of similar assets, manufacturer recommended lives, planned maintenance programs, anticipated changes in technological conditions and the related proportional weighting of the major components of the Allura Class Ships. We refer you to our Annual Report on Form 10-K for a discussion of the useful life and residual value assigned to Prima Class Ships.