(CNN) — You wake up and eat breakfast on your private balcony, admiring majestic views of the ocean.
You dock in port after port, crisscrossing the Mediterranean -- from the canals of Venice to the red roofs of Dubrovnik and back. Or you travel down the German Rhine or beach-hop in the Caribbean.
At each spot, you spend anywhere from a few hours to a day. Sometimes you don't even get off the boat. When you do, you're part of crowds of tourists, battling to see the views, scrambling to admire the sites.
The cruise ship industry is booming. Ships are getting bigger, better, more exciting and more experience-driven.
At the same time, ports are getting busier and more polluted, and residents are getting angrier.
In 2019, 30 million passengers are expected to cruise, up from 17.8 million a decade earlier. So what impact are they having on destinations, and what can be done about it?
"The whole tourism market is growing extremely rapidly," says Martyn Griffiths of the Cruise Lines International Association (CLIA), an association of cruise companies. "But we're still a very small part of tourism as a whole."
Griffiths is keen to place the cruise ship boom in context, saying that in increasingly crowded cities like Venice, Dubrovnik or Barcelona, ships only account for 5% of visitors. "So even if we were to take cruising away from those destinations, it really wouldn't address a lot of the overtourism problems that we see," he tells CNN Travel.
In Venice, the No Grandi Navi movement has been campaigning against cruise ships for several years.
MIGUEL MEDINA/AFP/Getty Images
Certainly it's true that cruise ships are just one part of a multifaceted issue. Recent years have seen a general rise in tourism, much of it concentrated in the same places. According to the World Tourism and Travel Council, of the 1.4 billion international tourist trips in 2018, half a billion of those were to the 300 most popular cities.
“The residents suffer very much, and it's beginning to feel like we're being deprived of our civil rights.”
Social media's probably playing a role too. Even CLIA cites "Instagrammable cruise travel" as a 2019 travel trend in its latest State of the Industry report. Plus, alongside more cruisers, there's more availability of budget flights.
Still, some parties concerned about the tourism crush point the finger directly at cruise ships because they say they encourage day trips where visitors are less likely to inject money into the destination's economy if they only stay a few hours.
Meanwhile, the scheduled arrival times of cruise ships mean thousands of visitors surge on a city all at once, rather than the flow of travelers being more spread out across the day.
There have also been concerns raised about pollution. A recent report from sustainable travel group Transport & Environment suggested that over the course of 2017, Carnival Corporation, a cruise operator that encompasses 10 cruise line brands including Cunard, Holland America and P&O, emitted nearly 10 times more sulphur oxide around European coastlines than all 260 million European cars. Venetian Jane da Mosto, co-founder and executive director at We Are Here Venice, a non-profit association that aims to address issues plaguing the Italian city, is unflinching in her assessment of how cruise ships impact the city.
"The residents suffer very much, and it's beginning to feel like we're being deprived of our civil rights," she says, arguing that it is the "very concentrated flows from cruise ships" that cause the city to become unlivable for Venetians.
"I think that Venice shows us very clearly how incompatible the gigantic cruise ships are for the city and for its physical and environmental security," da Mosto tells CNN Travel.
"The cruise ship industry needs to take the resistance and fragility of Venice as a signal that their business model has become unsustainable, unethical and very, very damaging."
Cruise ships fight back
Cruise ships might funnel thousands of people to destinations, but the companies don't operate in a vacuum.
Griffiths, of industry organization CLIA, points out that itineraries are planned two years in advance and organized in collaboration with destination officials.
Cruise ship companies including Royal Caribbean and MSC were contacted for this article, but redirected queries back to CLIA. The organization is the voice of the industry, and wields significant power. Griffiths acknowledges this, and says the association is keen to evolve with the times.
As for the economy question, he says the idea that cruise ships don't bring money to a destination is a "misunderstanding."
"A cruise line is paying a huge amount of money to the port and to the local authorities to dock and to be serviced in the port. On top of that, we use local people to deliver excursions."
"So we're investing money into the destination. It may not be seen in the local pizzeria or the local bar. But actually we're still investing very heavily in the destinations we visit."
Tourism trade is integral in many of the cities that are feeling the brunt of overtourism. Earlier in 2019, Venice's Port Authority President Pino Musolino told CNN Travel that cruise ships create up to 6,000 jobs for the city.
In 2017, the cruise ship industry generated an estimated $134 billion in economic impact globally.
Opponents would argue it's not all about money, though. What about the impact of the crowds?
It's not just locals who notice crowds flocking in droves to Barcelona's Sagrada Familia or traipsing across Dubrovnik's Old Town walls. Visitors feel the effects too.
Sue Bryant, cruise editor at the UK's Sunday Times newspaper and longtime cruise devotee, tells CNN Travel the increase in crowds in busy ports has impacted her enjoyment during recent excursions.
But the responsibility's not just on officials and cruise companies, she says, pointing out that travelers can try to be more thoughtful and imaginative.
"For example, if your ship overnights in Dubrovnik, go into town at sunset, a magical time, when most day trippers have left," she suggests.
"Spend the day at the beach instead of queuing up to walk the ramparts in the heat. Ditto Venice; try to avoid San Marco in the middle of the day, when it's a nightmare. Wander round after dark instead, or during the day, take a boat trip out into the lagoon."
Bryant also suggests considering a smaller ship and making an effort to spend money locally, staying on for a few days before or after your cruise or picking a cruise that runs in the off season.
Cruise ship passengers tend to disembark all at once, which can cause overcrowding.
ANDREA PATTARO/AFP/Getty Images
Passengers can do their own research to attempt to avoid being part of hordes of visitors trying to do the same thing at once.
The website Avoid-Crowds.com gives visitors information on when destinations are likely to be busy, sourced via publicly available tourism data. Punch in a date and location and the site rates how big crowds will be on a scale of 1 to 100. It also tracks public holidays in the destination, in addition to which cruise ships are in port that day.
The site says its aim is to help the travel industry and local governments by mitigating the effects of overtourism.
Cruising in the Caribbean
Cruise ships spotted in Nassau, Bahamas
DANIEL SLIM/AFP/Getty Images
European cities aren't the only destinations being transformed by cruising. Cruise tourism in the Caribbean brings in vital revenue for many smaller ports and island nations, but the region is also heavily impacted by the booming industry.
"Managing the flow of tourists embarking from cruise ships is a challenge in some Caribbean ports, just as it is in places like Venice, Dubrovnik and Barcelona," Brian Major, executive editor for Caribbean and Latin America at US content company travAlliancemedia, tells CNN Travel.
Before his current role, Major worked as a cruise industry trade reporter and he also did a stint at CLIA, so he's seen the industry from both sides.
"I think folks who live locally have feelings about the influx of tourists from cruise ships into a port that's relatively small," he says.
Major says communication with communities and cruise companies is key. He also points towards cruise operators including MSC and Royal Caribbean -- which are building their own ports in the Caribbean to redistribute traffic.
"The cruise companies are cognizant that their ships are growing larger and there are fewer and fewer ports they can call at that there won't be a significant impact," he says.
As well as dealing with overcrowding, there's definitely some truth, adds Major, to the criticism that some passengers don't get off the boat and spend money in the port.
"But I can tell you from the inside from having worked at the cruise lines -- the best-selling cruise itinerary, they sell them off the destination -- they sell because they're going to Montego Bay or because they're going to San Juan or because they're going to Belize," he says.
US cruises that just navigate around Florida aren't nearly as popular, he adds.
"Most of the people on a ship want to go to the destination. Are there people who are not going to get off? Sure there are. But most of the people want to go to the destination."
Some ports are perhaps better positioned than others to handle a big influx of visitors, but pollution is a question all destinations grapple with.
"It's no different from Machu Picchu or the Himalayas, or any other fragile, historic or cultural or natural environment we have that everyone wants to visit," says Major.
"The cruise lines, the tour provider -- they need to be operating at peak level when it comes to environmental responsibility. And I'm not always sure that always happens."
In Venice, da Mosta says she isn't interested in cruise ships docking for longer in an attempt to bring in more money, if the trade-off is more air pollution.
Venice was pinpointed by Transport & Environment as the third most ship-polluted port. Barcelona topped the list, with Palma de Mallorca, Spain -- where residents signed a petition calling for a one-cruise-ship-per-day limit -- coming up third.
While cruise companies might enjoy advertising in superlatives, it's not cool to be unsustainable any more -- and as many of us become aware of our carbon footprint, some companies are promoting smaller, apparently more eco-friendly vessels.
But just how green are these concepts?
"I am happy to see eco initiatives in the cruise industry. I do think some are very genuine," says Samantha Bray, managing director at the Center for Responsible Travel.
"But I do think there is also a fair amount of greenwashing going on, and that a lot more has to be done by the cruise industry."
The various sectors need to work together and listen to residents, suggests Bray -- a sentiment other experts echo.
"In recent years the cruise industry has done a better job of trying to communicate with communities and manage the flow, but there's definitely work to be done," says Major. "Particularly as the cruise ships are not growing smaller, they're growing larger."
Bray says the cruise industry needs to take prompt action if it's to sustain its own business model.
"We're at a critical breaking point now, and we can't just talk the talk anymore," she adds. "They have to be walking the walk if we want destinations to be viable destinations for cruises in the future."