Guests will need to provide proof of vaccination before embarkation, including evidence of having received both vaccine doses if required by the manufacturer.
At least a full 14 days must also have elapsed since their full inoculation.
A vaccination requirement forms part of the line’s new Crystal Clean+ 4.0 measures, which includes negative Covid tests for guests and crew, pre-departure temperature checks, what it describes as a "nimble" mask policy, some social distancing, enhanced cleaning and disinfection, reduced capacity, and other protocols.
"We are encouraged by the progress being made with the Covid-19 vaccines and what this means for Crystal and the travel industry," said Crystal interim president and chief executive, Jack Anderson.
Anderson said a vaccine requirement was "simply the best way to ensure the safest possible Crystal experience for all on board". "This sentiment is underscored by conversations with our guests and travel partners," Anderson added.
Owing to the varied progress of vaccination programmes worldwide, Crystal has announced it will pause river operations through to the end of May and ocean operations into June.
Crystal Esprit won’t return to service until 1 August, while Crystal Endeavor’s operations have been suspended into August.
The line said it believed this timeline would be sufficient to allow "most travellers" to be fully vaccinated ahead of any resumption of sailing.
All Crystal crew will be expected to be vaccinated when the line resumes sailing, although it has stressed this may not be a viable option for all crew owing to their age and/or the availability of vaccines in their home countries.
Crew will be required to test negative before they leave their home location to join the ship. They will then have to take a Covid test upon embarkation and quarantine for seven days, and test negative again before beginning their duties.
"When vaccines are widely available, they will be a requirement of employment for crew which must be completed at least 14 days prior to service," Anderson confirmed.
Guests, meanwhile, will have to complete an online form acknowledging the line’s vaccination requirements before their tickets are issued.
Crystal joins Saga in confirming it will require guests to be vaccinated.
