A Royal Caribbean-owned cruise line just announced a vaccine requirement. These are all the cruise lines that will require COVID-19 vaccinations for guests and crew.

• The return of cruising still remains in limbo for many cruise lines.
• Companies including Royal Caribbean and Norwegian have announced vaccine requirements.
• These are all the cruise lines that have COVID-19 vaccine requirements for guests or crew.

Several cruise lines have started announcing vaccination requirements for guests and crew members as the industry looks to restart after the the COVID-19 pandemic.

Last year, cruise ships that were mid-trip began facing COVID-19 related turmoils as the virus began trickling around the world, leaving passengers stuck, infected, or dead. Shortly after, the US Centers for Disease Control and Prevention issued a no-sail order, which was later replaced by its "Framework for Conditional Sailing Order," a compilation of protocols needed for cruising to resume again by November 1.

This sailing order was again updated on April 2. These new guidelines didn't reflect the cruise industry's hope of a sailing return by July, but did recommend cruise lines to establish a timeline for crew and port workers to get the vaccine.

Despite this updated framework - and pent-up demand for highly anticipated cruise ships and trips - the official return of cruising still remains in limbo. Presently, no major US cruises will be welcoming passengers until May, but companies are constantly extending this pause on sailing.

But as the COVID-19 vaccine continues to be distributed across the globe, this could soon change.

"If we start to see vaccines become more widely available, and if the vaccines are being administered in a far more efficient manner than they have been, I think it would be reasonable for the cruise lines to say a vaccine is required," Henry Harteveldt, a travel industry analyst and president of the Atmosphere Research Group, told Insider in an interview.

However, vaccine rollout and accessibility has been a notorious struggle around the world. As a result, Harteveldt notes that it may be "counterproductive" for major cruise lines like Carnival and Norwegian to require its guests to receive the vaccine if sailings actually resume in the next few months instead of later in the year, say July.

But over the last month, cruise lines have become increasingly vocal about the vaccine. While some companies - such as Carnival and its Holland America line - are "reviewing" the different vaccines, several others have already announced vaccination protocols for guests and crew members.

These are all the cruise lines with vaccine-related mandates so far:

Saga Cruises

On January 21, United Kingdom-based Saga Cruises announced that it would require all of its passengers to be fully vaccinated against COVID-19 two weeks before a trip. Saga primarily caters to passengers over 50-years-old.

Royal Caribbean

Royal Caribbean expects to require its crew members to receive the vaccine before sailings return, a spokesperson told Insider.

On March 1, the cruise line also announced its first "fully vaccinated" cruise aboard the Odyssey of the Seas, which will be sailing in May from Israel. Both crew members and guests over 16 years old will have to be vaccinated against COVID-19 in order to sail on the upcoming cruise.

"Royal Caribbean's decision to come to Israel is a significant expression of confidence in our policy," Prime Minister Benjamin Netanyahu said in the press release announcing the cruise. "Just as we made Israel the world champion in vaccines, we will make it the world champion in economics and tourism in the post-coronavirus era."

On March 19, Royal Caribbean announced a similar series of seven-night sailings from July to August aboard its Adventure of the Seas ship. These summertime cruises will bring guests from Nassau, Bahamas to islands like the Grand Bahama, Cozumel, Mexico, and Royal Caribbean's Perfect Day at CocoCay.

Like the Israel-based Odyssey of the Seas sailings, every adult passenger interested in this upcoming Adventure of the Seas collection will have to be vaccinated against COVID-19. Guests under 18-years-old will instead have to test negative for the virus.

"The vaccines are clearly a game-changer for all of us, and with the number of vaccinations and their impact growing rapidly, we believe starting with cruises for vaccinated adult guests and crew is the right choice," Michael Bayley, president and CEO of Royal Caribbean International, said in a press release. "As we move forward, we expect this requirement and other measures will inevitably evolve over time."

On March 23, Royal Caribbean announced another set of seven-night summer cruises, this time from Bermuda aboard the Vision of the Seas ship. Like its previous announcements, these new cruises - which will sail from June 26 through August - will require crew members and adult guests to be vaccinated against COVID-19 "at this time." Passengers under 18 years old will instead have to test negative for the virus.

Guests aboard this recently announced "fully vaccinated" summer cruise will get a full day at Perfect Day at CocoCay and an overnight stay in Bermuda.

One day later, the mega cruise line announced another set of fully vaccinated seven-night cruises, this time from Limassol, Cyprus. These cruises, which will sail from July 10 through October, will bring guests around Cyprus and Greece, including tourist hotspots like Athens, Mykonos, and Santorini. The same crew, adults, and guests under 18 years old health protocols from the prior two Royal Caribbean announcements apply to this sailing as well.

Crystal Cruises

On February 18, Crystal Cruises said it would require guests to receive both doses of the COVID-19 vaccine at least 14 days before a cruise. The cruise line is also requiring a negative coronavirus test result from travelers and crew members, among other health protocols.

"We know that peace of mind is the greatest luxury, and the vaccine requirement is simply the best way to ensure the safest possible Crystal Experience for all on board," Jack Anderson, the cruise line's interim president and CEO, said in a press release.

Hornblower Group's "overnight" cruise lines

Hornblower Group's American Queen Steamboat Company and Victory Cruise Lines have both announced requirements for guests and crew members to receive the COVID-19 vaccine for sailings starting July 1.

According to John Waggoner, CEO and founder of American Queen Steamboat Company, requiring the vaccine will ensure the "safest cruising experience possible." However, the cruise lines is are still looking to resume sailing in April, prior to this vaccination deadline.

Norwegian Cruise Line and its Oceania and Regent Seven Seas Cruises brands

Norwegian Cruise Line and its Regent Seven Seas Cruises have announced COVID-19 vaccine requirements for crew members prior to boarding. However, the cruise lines are still "exploring all options" in regards to vaccination requirements for its guests, according to the cruise lines' statements previously sent to Insider.

Now, it seems like Norwegian has made up its mind regarding guest vaccination mandates. On April 5, Norwegian Cruise Line Holdings announced that its three cruise brands - Norwegian, Oceania, and Regent Seven Seas Cruises - will be requiring both guests and crew members to be fully vaccinated.

"Norwegian Cruise Line Holdings shares the CDC's view that vaccinations are the primary vehicle for Americans to get back to their everyday lives," Frank Del Rio, president and CEO of Norwegian Cruise Line Holdings, said in a press release. "We believe that through a combination of 100% mandatory vaccinations for guests and crew and science-backed public health measures ... we can create a safe, 'bubble-like' environment for guests and crew."

Now, Norwegian is hoping the CDC will allow it to bypass the Conditional Sailing Order, therefore bringing the cruise line's sailings from US ports back by July 4.

Virgin Voyages

Richard Branson's adults-only cruise line, Virgin Voyages, has announced it will be making the COVID-19 vaccine mandatory for both guests and crew in order to "provide the safest travel experience," Tom McAlpin, Virgin Voyages' CEO, said in an email statement sent to Insider.

"The is a step towards the safe return to sailing and is the right decision for Virgin Voyages," McAlpin said in the statement. "We're really encouraged by the latest rollout plans in the May time frame from the new administration, and we know the future is about vaccinations. Our business makes us uniquely set up to do this with testing and vaccine travel requirements."

P&O Cruises

On March 17, P&O Cruises - owned by Carnival Corp - announced a summertime Ultimate Escape cruise collection that will sail along the UK coast. However, the cruises will only be available to UK residents who have been fully vaccinated against COVID-19 at least seven days before the trip.

The decision to make COVID-19 vaccinations mandatory for guests was based on the "advanced progress of the UK vaccination program and strong expressed preference on the part of our guests," P&O said in a press release.

Celebrity Cruises

On March 19, Royal Caribbean's Celebrity Cruises announced seven-night Caribbean sailings departing from June 5 to August aboard the Celebrity Millennium ship.

Like its parent company's sailings, all crew members and adult guests interested in Celebrity's summer Caribbean cruises will have to be vaccinated against COVID-19. People under 18 years old will instead have to receive a negative PCR test result within 72 hours of the trip.

Windstar Cruises

On March 30, US-based Windstar Cruises announced a COVID-19 vaccine requirement for its guests and crew.

Guests interested in sailing with the small cruise line - which oversees six ships - must be fully vaccinated at least 14 days before sailing. Proof of the vaccination and a negative COVID-19 PCR test will then have to be presented in order to board the ship.

Windstar's crew will also have to be vaccinated "as soon as the vaccine is available to them," according to the cruise line.

Cunard

Cunard will resume sailing with cruises around the UK aboard the Queen Elizabeth ship from July to October. However, don't consider booking a trip unless you're a UK resident that's been vaccinated against COVID-19.

Guests interested in Cunard's summer cruises must be fully vaccinated at least seven days before sailing, and will be required to show proof.

Seabourn

On April 6, Seabourn - owned by Carnival Corporation - announced its new seven to 14-day Mediterranean sailings to and from Athens, Greece starting July 3. From there, passengers will get to see tourist hotspots like Mykonos and Agios Nikolaos, Greece and Limassol, Cyprus.

Like other cruise lines, Seabourn is requiring all guests interested in this upcoming summer cruise series to be fully vaccinated at least 14 days before cruising.

Viking

The same day Seabourn announced its new fully vaccinated sailings, Viking also unveiled three new eight-day summer cruises, all with a vaccine mandate. These new itineraries will each sail around three different locations starting June: Bermuda, the UK, and Iceland.

Despite the guest vaccine requirement, guests and crew will still have to take a PCR test as well.

"We believe there will be no safer way to travel the world than on a Viking voyage," Torstein Hagen, Viking's chairman, said in the press release."

Silversea

On April 8, Royal Caribbean-owned Silversea announced it would require guests and crew - with the exception of those sailing aboard its cruises from Australia - to be fully vaccinated. That same day, Silversea also unveiled its plans to resume sailing on June 18 with 10-day Mediterranean cruises from Greece aboard the Silver Moon ship.

"Vaccinations will play a critical role in ensuring the health and safety of our guests, crew, and the communities we visit, which we prioritize above all else," Roberto Martinoli, president and CEO of Silversea Cruises, said in a press release.

Are you a cruise industry employee or have a cruise industry story to share? Contact this reporter at bchang@insider.com.