That is more than 6 weeks added to the originally intended return to service in mid-May across the 3 brands.
Like most cruise companies, cancelled sailings can be refunded, or clients can apply the money to a future voyage. NCL is offering 125% cruise credit for guests who were booked on journeys from March 18 through June 30 for new bookings that can be sailings through December 31, 2022. Both Oceania and RSSC-Regent have the same 125% credit program.
Norwegian Cruise Line is also offering a 20% discount on new bookings for any sailing between October 1, 2020-December 31, 2022 if they're made before May 15, 2020.
The moves come as cruise companies are still under the “no sail order” of the CDC (Centers for Disease Control and Prevention) for all cruise vessels from U.S. ports originally enacted March 14 and updated earlier this month that potentially extends through July 17, 2020. The order would not apply to cruise companies sailing to/from other nations around the globe, but some such as Canada, have already closed ports.
Carnival Cruise Line cancelled all voyages through June 26 along with all sailings from San Francisco CA through 2020, all Carnival Sunrise journeys through October 19, all Carnival Legend sailings through October 30, and all Carnival Radiance cruises through November 1.
For Coronavirus updates on cruise ship quarantines (infected passengers and crew) and top-pandemic countries (COVID-19 cases and deaths, daily updated statistics) see at CruiseMapper's Norovirus page.