Royal Caribbean is not the only cruise line to announce it will restart cruises from the U.S. this summer.

Both Carnival Cruise Line and Norwegian Cruise Lines announced on Monday plans to restart cruises as early as July.

Royal Caribbean lead the restart plan charge last week, when it announced cruises from the U.S. in July and August, signifying a major milestone in the cruise industry's return to service.

Here is a look at what each of the other major cruise lines announced today.

Carnival will restart in July

Carnival confirmed it will return to service with cruises out of Galveston on two ships.

Carnival Vista will sail on July 3rd from the Port of Galveston, followed by Carnival Breeze on July 15.

These cruises are available for guests who have received their final dose of a CDC-approved Covid-19 vaccine at least 14 days prior to the beginning of the cruise and have proof of vaccination, in accordance with current guidelines from the U.S. Centers for Disease Control and Prevention (CDC).

Carnival also has plans to restart cruises on the Carnival Horizon from PortMiami in July.  No specific date was shared, as the line is working with the State of Florida and the CDC for Carnival Horizon sailings.

Carnival also said plans to provide an update by Friday concerning protocols specific to these sailings to all booked guests.

August sailings will be announced by Carnival "over the coming days."

Norwegian will restart in August

NCL admitted its restart plans in the U.S. are contingent on obtaining a conditional sailing certificate from the U.S. Centers for Disease Control and Prevention and Norwegian Cruise Line Holdings Ltd. said that all its initial voyages will operate with fully vaccinated guests and crew.

First, NCL said it would replace Norwegian Bliss on its Alaska cruises with the Norwegian Encore instead.

In terms of new U.S. sailings, here is what NCL announced:

• Norwegian Gem will begin sailing 7-night cruises from PortMiami on August 15
• Norwegian Breakaway will sail to Bermuda from New York on September 26
• Norwegian Bliss will sail from Los Angeles to the Mexican Riviera on October 2
• Norwegian Escape will sail from Port Canaveral on November 13

Frank Del Rio, president and chief executive officer of Norwegian Cruise Line Holdings, said the additional planned U.S. voyages build on earlier plans for 23 of the company's 28 ships across its three brands beginning in July and phasing in through early 2022.

Carnival Cruise Line is moving forward with its restart plans from the United States.

Carnival announced the U.S. Centers for Disease Control & Prevention’s (CDC) has approved its plans in place with three major cruise ports.

Specifically, Carnival now has agreements with PortMiami, Port of Galveston and Port Canaveral that have been approved by the CDC under Phase 2A of the Conditional Sail Order (CSO).

These port agreements are part of the Phase 2A of the CSO and need to be signed by executives from the cruise line, as well as port and state health authorities, as will as be approved by the CDC.  The agreement explains what the cruise terminal would do in the case of Covid-19 cases on a cruise ship, as well as how it intends to keep the cruise terminal and gangways sanitized.

Royal Caribbean has a similar agreement with PortMiami, Port Everglades, and Port Canaveral.

With the port agreements in place, it supports Carnival's plans to restart Carnival Horizon from PortMiami, and Carnival Vista and Breeze from Galveston.

Port Canaveral has also been identified as a restart priority, and Carnival expects to announce plans for operations from there over the coming days.

"These agreements move us one step closer to sailing with our loyal guests,” said Lars Ljoen, executive vice president and chief maritime officer for Carnival Cruise Line.  

“We appreciate the support from not just these three homeport partners, but all of our homeports, that are eager to have us back as soon as possible.”

The agreement will also include information social distancing guidelines and plans for using commercial operators for any required evacuations at sea.

Each cruise line must have signed contracts with shore-side medical facilities to treat patients and shore-side housing facilities to isolate and quarantine sick passengers.

With the port agreements in place, likely Carnival will either need to apply for approval for test cruises, or skip test sailings if they can get at least 95% of its passengers vaccinated.

Royal Caribbean International has opted to conduct test cruises, but Celebrity Cruises will be able to skip them since they can get at least 95% of their passengers vaccinated.

Carnival Cruise Line appears to be ready to start the first of its test cruises in a matter of weeks.

During a meeting of the Board of Trustees of Galveston Wharves, the Port of Galveston said Carnival plans to run its test cruises from the port, although no exact date was set.

The Galveston County Daily News reports Carnival has informed the port of its plans.

According to the report, the Port of Galveston and local health officials say they are close to signing a port agreement with the State of Texas.  Royal Caribbean recently signed similar agreements with Port Canaveral and Port Everglades.

It also appears that Carnival will follow Royal Caribbean's plan to not make the optional 95% vaccinated cruise ship passenger mandate in order to skip test cruises.

The U.S. Centers for Disease Control and Prevention (CDC) gave cruise lines the choice of going through the test cruise option outlined in the Conditional Sail Order (CSO), or skip them if they can reach 98% of crew and 95% of passengers fully vaccinated.

Royal Caribbean Group Chairman and CEO Richard Fain said yesterday in a video update that Royal Caribbean International cannot meet that goal of 95% vaccinated passengers because of all the families with young children who go on a cruise. 

Carnival plans to run simulated cruises out of Galveston in coming weeks, port officials just announced at Wharves Board of Trustees meeting. No exact date set. #GalvNews https://t.co/WmJIb7EinP

— John Wayne Ferguson (@JohnWFerguson) May 25, 2021

The Port of Galveston was told by Carnival's President that standard would be difficult, since vaccinations aren't yet available for children under 12 . That's a significant portion of their normal customer base.

Royal Caribbean is also planning to start test cruises soon, although the location nor the ship to be used has been shared publicly. 

Royal Caribbean applied to be able to start at least one test cruise last week, and the cruise line expects that authorization to be granted "shortly".

The simulated voyages are the test sailings mandated by the CDC in order to receive permission for a cruise ship to sail from the United States.

Under the CDC's Framework for Framework for Conditional Sailing Order (CSO), cruise lines must first get an agreement with each port for the health and safety of crew, passengers and port personnel.

Test cruises are when cruise lines can operate ships with volunteer passengers in order to prove their new protocols work.

Hours after new legislation has opened the door for cruises to Alaska, Carnival Corporation announced plans to offer cruises there this summer.

Carnival Corporation announced three of its brands, Carnival Cruise Line, Princess Cruises and Holland America Line, will offer cruises to Alaska this year.

The new sailings will begin in July, and depart from Seattle, Washington.

The announcement was made a few hours after the U.S. House of Representatives passed a Bill to allow cruise ships to sail to Alaska without stopping in Canada.

Carnival said each of the lines has received guidance from the U.S. Centers for Disease Control and Prevention (CDC), as well as coordinated with Alaskan officials in order to sail again.

It is not clear what this guidance is exactly since the Conditional Sail Order is still in effect, but the line issued a statement that it seemingly has the go-ahead to make these cruises happen.

These Alaska cruises are available for guests who have received their final dose of an approved COVID-19 vaccine at least 14 days prior to the beginning of the cruise and have proof of vaccination. Crew vaccinations will be in accordance with CDC guidelines.

Princess Cruises will resume operations in Alaska starting July 25 through September 26, with seven-day cruises onboard Majestic Princess, a MedallionClass ship.

Its cruises will visit signature ports, glaciers and attractions in Alaska including Glacier Bay National Park, Juneau, Skagway and Ketchikan.

Holland America Line will resume its cruise operations to Alaska with seven-day itineraries aboard Nieuw Amsterdam, calling at Juneau, Icy Strait Point, Sitka and Ketchikan, with scenic cruising in Alaska's iconic locales, including Glacier Bay and Stephens Passage.

The first cruise for the brand is scheduled to depart July 24, with 11 Saturday departures that will operate through October 2.

Carnival Cruise Line has already opened Alaska sailings departing from Seattle beginning July 27, with weekly departures through September 14 aboard Carnival Miracle. There are seven 7-day cruises featuring calls in Juneau, Skagway, and Ketchikan, as well as scenic cruising in Tracy Arm Fjord.

The September 14 departure is an 8-day cruise with an additional stop in Icy Strait Point.

Carnival Corporation also said plans for these itineraries to fulfill obligations under the Passenger Vessel Services Act (PVSA) are expected to be approved. Princess Cruises, Holland America Line and Carnival Cruise Line are each continuing the return-to-cruising preparation already underway.

Each of the lines will announce more details in the coming weeks.

More U.S. sailings to come

Carnival Cruise Line is also working to finalize its plans to operate Carnival Horizon from Miami, and Carnival Vista and Carnival Breeze from Galveston in July.

Itineraries along with specific details about protocols are expected to be finalized and announced next week.

Carnival Cruise Line confirmed on Monday it is in active discussions to restart cruises from the United States as early as July.

All eyes are on which cruise lines will be able to restart cruises from the United States, which requires permission from the U.S. Centers for Disease Control (CDC).

Carnival Cruise Line President Christine Duffy said in an interview with NBC Nightly News the cruise line is working with the CDC to gain permission to restart sailings in July, which will carry no vaccine mandate for passengers in order to sail.

Ms. Duffy said Carnival and the CDC are "working through the details" of sailing again in July.

Carnival wants to jump on the initiative by President Joe Biden to reopen the country by Independence Day on July 4, "I think the CDC and the interagency groups that are working with us now have that same goal in mind as President Biden said."

"He wants to reopen America by the Fourth of July and we want to make sure that the cruise industry can be part of that reopening of America."

Duffy was asked about getting every passenger and crew members vaccinated, and while she supports getting everyone vaccinated, it is something that no other industry is having to decide to do, "There's no mandate for any other business to have that requirement.

"We certainly are encouraging everyone to get a vaccine. I think, again, we don’t want to be treated differently than any other part of travel tourism, entertainment, or society."

The other issue with requiring the vaccine of all passengers would be children under the age of 12, which Ms. Duffy said is important to the cruise line, "children under 12 are a big part of the cruise experience in a summer, you know a family vacation, and as it stands right now, we wouldn’t be able to have kids under 12 on board."

Ms. Duffy also spoke about the significant economic impact no cruise ships are having on the U.S. economy in jobs and spending, "There’s a huge impact obviously to jobs in the cruise industry but also what people don’t think about is all of the indirect impacts that we have, if you take a place like Alaska, where the bulk of tourism comes from people who sail on cruise ships."

"We employ about 500,000 people in the U.S.and we’ve lost about 300,000 direct jobs at this point."

Carnival's restart plans are more than just talk. The line has a handful of ships held back for a potential restart in July from ports in Florida, Texas, and Washington.

There are three ships that are not cancelled for July, including Carnival Vista and Carnival Breeze from Galveston, and Carnival Horizon from Miami. 

Carnival also said if there is an option to sail to Alaska, then the Carnival Miracle will takeover sailings for Carnival Freedom from Seattle.

Carnival is also the only cruise line among the major lines not to announce restart plans outside the United States.

Norwegian Cruise Line will sail from the Caribbean and Europe this summer, and Royal Caribbean will do the same.

Carnival Cruise Line announced it has cancelled some of its July 2021 cruises, but there is still hope for some ships to sail from the U.S. in July.

Carnival says there is a a possible July restart in the U.S. on select ships from Florida and Texas.

There are three ships that are not cancelled for July, including Carnival Vista and Carnival Breeze from Galveston, and Carnival Horizon from Miami. 

Carnival also said if there is an option to sail to Alaska, then the Carnival Miracle will takeover sailings for Carnival Freedom from Seattle.

All other July 2021 cruises are cancelled through July 31, 2021.  Guests booked on those sailings who wish to make alternate summer vacation plans may cancel without penalty by May 31, 2021 and receive a full refund. 

The cruise line is also giving guests the choice of canceling now instead of waiting to see what happens.  Guests booked on those sailings who wish to cancel without penalty can do so by May 31, 2021 and receive a full refund. 

Carnival Cruise Line President Christine Duffy said the line is still working with the CDC for a July restart, "We continue to have constructive discussions with the CDC but still have many questions that remain unanswered.  We are working diligently to resume sailing in the U.S. and meet the CDC guidelines."

"We sincerely appreciate the continued patience and understanding of our guests and travel advisor partners and will share additional information as quickly as we can."

Carnival joins Norwegian Cruise Line in canceling some, but not all, of its July cruises. Unlike NCL, Carnival is holding back ships for a possible U.S. restart.

Norwegian Cruise Line Holdings CEO Frank Del Rio told investors last week that a July restart for his company was "not possible."

"The July U.S. launch, at least for our company, is just not possible,” Del Rio confessed.

"It was possible back in early April when we proposed to the CDC 100 percent vaccination, so from April 5, 90 days would be early July so that was possible."

What will Royal Caribbean do?

Royal Caribbean has not announced what it will do about July sailings from the United States yet.

Royal Caribbean rarely gives any kind of warning when a new set of cancellations are going to occur, but with Carnival and NCL both announcing additional cancellations for July, it seems Royal Caribbean must be close to making a similar decision.

Of course, Royal Caribbean will sail a handful of ships in July from outside the United States from countries like Bermuda, Bahamas, Israel, Singapore, Cyprus and England.

The rest of the ships and sailings scheduled in July are all still to be determined.

Another major cruise line has cancelled its June cruises, leaving just Royal Caribbean as one the "big three" cruise lines with June sailings on the books.

Carnival informed guests on Tuesday that it will extend its cruise cancellations from U.S. ports through June 30, 2021.

To provide flexibility for guests booked on July itineraries that remain in the schedule, Carnival is extending final payment deadlines for all July sailings to May 31, 2021, with the ability to cancel without penalty.

Norwegian Cruise Line also cancelled its June 2021 cruises back on March 16, 2021.

Prior to today's announcement, Carnival had cancelled cruises through May 31, 2021.

As it has done throughout the pause, Carnival is providing guests on cruises cancelled today the choice of a future cruise credit plus onboard credit package, or a full refund.

In their announcement, Carnival said, "We know that this is very disappointing to our guests who continue to be eager to sail, and we remain committed to working with the Administration and the CDC to find a workable solution that best serves the interest of public health."

Carnival Cruise Line President Christine Duffy implored the U.S. Centers for Disease Control (CDC) to treat the cruise industry fairly, "We are asking that the cruise industry be treated on par with the approach being taken with other travel and tourism sectors, as well as U.S. society at large."

Ms. Duffy also said there are no plans yet to base its ships outside the United States, but that option may become inevitable if things do not change, "While we have not made plans to move Carnival Cruise Line ships outside of our U.S. homeports, we may have no choice but to do so in order to resume our operations which have been on ‘pause’ for over a year."

"We appreciate the continued patience and support from our loyal guests, travel advisors and business partners as we work on a return-to-service solution."

Ms. Duffy was vocal about keeping ships sailing from the U.S. and not following Royal Caribbean's lead by sending ships outside the U.S. to restart.

In a meeting with Florida's Governor in March 2021, she was proud of the fact Carnival was making no such plans, "Here at Carnival we currently do not have any plans to move our ships away from their US homeports, I’ve always said Carnival Cruise Line is America’s cruise line."

"We sail from 14 US homeports, a significant number of our guests drive to their Carnival vacations, and we also sail with more families and children than any other cruise line."

What about Royal Caribbean?

Royal Caribbean has made no announcements yet about if it will cancel June 2021 cruises.

The line will be restarting operations in June on a few ships outside the United States including:

• Adventure of the Seas from Nassau, Bahamas
• Vision of the Seas from Bermuda
• Odyssey of the Seas from Haifa, Israel

Anthem of the Seas will restart in July, and Quantum of the Seas continues to sail from Singapore.

Read more: Is there a pattern to when Royal Caribbean cancels cruises?

The rest of the ships and sailings scheduled from June are all still to be determined, although many in the cruise industry expect more cancellations.

Royal Caribbean rarely gives any kind of warning when a new set of cancellations are going to occur.

While Royal Caribbean has not, another cruise line has cancelled its May 2021 cruises.

Carnival Cruise Line announced on Wednesday it will continue their suspension of sailings through May 31, 2021.

Cruises from U.S. ports are cancelled through May, but Carnival added that it is unsure when cruises might resume.

In their announcement, Carnival said, "A date for the return of guest cruising operations from U.S. ports has not yet been determined."

Carnival said in a statement that they will continue to work on plans to resume operations, and the vaccine progress is encouraging.

"We continue to work on plans to resume operations and are encouraged by the focus to expedite vaccine production and distribution which are having a demonstrated impact on improving public health."

Prior to today's announcement, cruises had been cancelled through April 30, 2021.

As it has done throughout the pause, Carnival is providing guests on cruises cancelled today the choice of a future cruise credit plus onboard credit package, or a full refund.

Carnival joins a few other cruise lines in canceling their May 2021 cruises, including Norwegian Cruise Line, Disney Cruise Line and Azamara.

What will Royal Caribbean do?

Royal Caribbeans want to know if/when Royal Caribbean may announce a new set of cancellations to match what the other cruise lines have done.

Royal Caribbean rarely gives any kind of warning when a new set of cancellations are going to occur.

Read more: Is there a pattern to when Royal Caribbean cancels cruises?

With final payment dates coming up, many cruise fans are eager to know what will happen to these sailings, as well as how many more of these cancellations we can expect to deal with.

Royal Caribbean Group Chairman and CEO Richard Fain said in a recent interview that cruise lines and the government will consider a variety of factors before cruises can restart.

"We just we're in the midst of a huge surge...over the end of last year," Mr. Fain explained. "Nobody was going to suggest that we start operating in that kind of environment."

"But as that's coming down, as the numbers get better, as the prevalence in society gets better, as the vaccine gets out there more, I think that's when we can start having serious conversations to restart."

Cruise fans looking for optimism about the return to service should look no further than Carnival Corporation CEO Arnold Donald's latest comments.

During a webinar, Mr. Donald told travel industry insiders that he thinks many of his brands ships will be cruising by the end of the year.

"What I will predict is this: I think that certainly by the end of this year, most, if not all, of our fleet, I’m optimistic, will be in action."

"I think there’s a really high probability that all of them will be back by early next year if things continue to progress the way they have."

Why is Mr. Donald so bullish on the return of cruises?

In short, he thinks a faster rollout of the vaccine, better treatments and low-cost testing are all working towards move the global health crisis away from a public health emergency.

"The combination of all that bodes really well and puts us in a good position," he said about the advances being made.

"The knowledge about covid has changed. The ability to manage covid has changed. All these things have moved in a positive direction."

Mr. Donald's comments echo similar comments from Royal Caribbean Group Chairman and CEO Richard Fain who has pointed to positive signs in the fight against covid.

Earlier this month, Mr. Fain touted the rollout of the vaccine and new health protocols as a key component to moving towards a restart.

"The vaccines and other steps we are taking are also important to protect the crew. In the beginning, it was really very difficult to ensure that the crew members were virus free. But the new vaccines, testing and other steps are giving us the opportunity to protect them as never before."

Speaking of the vaccine, Dr. Scott Gottlieb, co-chair of Norwegian Cruise Line Holdings’ and Royal Caribbean Group’s Healthy Sail Panel, told CNBC he believes covid vaccine appointments will be widely available by April in the U.S.

"I think we’re going to run out of demand sooner than we think. I suspect that in some point in March and certainly by the end of March, we’re going to have to make this generally available."

"That doesn’t mean everyone can go and get a vaccine on April 1, but I think everyone is going to be able to go online and get an appointment sooner than we think."

Dr. Scott Gottlieb was the Commissioner of the FDA from 2017-2019 and served as the agency’s Deputy Commissioner for Medical and Scientific Affairs from 2005- 2007.

He believes supply constraints will remain throughout February that justify having more narrow eligibility criteria. "But at some point in March, states are going to have to make decisions about how to open this up more widely."

About a day after Carnival Cruise Line posted its list of new health protocols for when cruises restart, they removed it from their website.  

Carnival posted on Friday their new rules that include wearing masks, social distancing, and restricting shore excursions. 

By Saturday, the protocols were taken down from their website and replaced with basic health requirements stipulated by the U.S. Centers for Disease Control (CDC).  

In the limited time the rules were posted, it generated a lot of comments from cruise fans in support and in frustration with the rules. 

Read more: Why shore excursions are the big change to cruises you aren't thinking about

According to Cruise Radio, Carnival says the rules were posted early and are not complete. 

"In our haste to keep guests and travel agents informed, we posted some information that was not finalized. As we have said previously, guests should expect [mask-wearing], testing, distancing and other protocols. We intend to provide more details over the coming weeks as we work to resume operations."

The new rules were similar to many of the new health protocols utilized by the few cruise ships able to restart operations, including Royal Caribbean's Quantum of the Seas in Singapore.

Avalanche of opinions of new rules

In the brief period of time the rules were posted on Carnival's site, there were plenty of opinions by cruise fans on what they thought of the protocols.

Hundreds of comments were posted on social media, including the RoyalCaribbeanBlog Facebook page.

A vocal group of comments came from those who flat out refuse to wear a mask on a cruise ship.  These cruisers have been largely upset masks are required in places like the pool deck, or even at all.

"I am NOT going on a cruise if I have to wear the mask," said Ben Breslin.

"As badly as we want to cruise, there is no way I’m wearing a mask or jumping through all these hoops to do it," added Dawn Thompson.

Read more: What is the best mask to wear on a cruise ship?

Many others were eager to get back onboard and willing to do what it takes to get cruises going again.

"I totally agree to all of these conditions," Christine Dale said.

"I’m ready for it all BRING IT ON!" said Tawny Simone Garcia-Berotte

Emerson Pratt thought the rules were what we should all expect, "I don’t think there is anything there we weren’t expecting. I think this is probably the standard all will adopt with additional protocols added depending on the cruise line/ship/country."

Still waiting on Royal Caribbean's rules

Whether or not Carnival's health protocols are going to include all of this or not, Royal Caribbean has yet to reveal their health protocols for cruises outside of Singapore.

The new protocols will be crafted by the Healthy Sail Panel, a joint venture between Royal Caribbean Group and Norwegian Cruise Line Holdings.

Many expect Royal Caribbean's rules to be very similar to the protocols on Quantum of the Seas, with a few tweaks that are not specific to Singapore's laws.

In summer 2020, the Healthy Sail Panel came up with 74 recommendations for cruise ships to operate safely during the health crisis, and they have since become the cornerstone of the cruise industry's approach to a healthy return to sailing.  

The next step is to turn those recommendations into cruise line policies.

Read more: 5 things you've probably overlooked with the new cruise protocols