Crystal Cruises has extended the cancellation of ocean sailings until the end of May.
The measure affects 14 Crystal Serenity and Crystal Symphony itineraries in Europe.
The luxury line said: “Unfortunately, the continually changing variables related to Covid-19 – including differing border restrictions, potential quarantine policies for various nationalities, and limited international airlift – continue to determine when, and where, this can happen.
“The uncertainty surrounding this global health crisis hinders the ability for cruise lines to operate, and it is with deep regret that we have had to cancel all voyages aboard Crystal Serenity and Crystal Symphony with departures through May 2021.
“We extend our deepest apologies for this situation that is beyond our control and remains a great frustration to us all.
“Everyone at Crystal, along with the officers and crew of our ships fleet-wide, are very disappointed that we are compelled to take this action, but we will only return to cruising when it is deemed safe to do so by governing health authorities, and when international travel constraints allow.”
Affected passengers and agents are being contacted with details of the cancellations along with compensation and rebooking options.
Voyages by Crystal Esprit were cancelled before Christmas until the end of April.