A man knelt and kissed the carpet adorned with the ship’s logo. Another picked up her wife and spun her around, ecstatic to be among the approximately 5,000 passengers who would embark on the inaugural sailing of the world’s largest cruise ship, the Icon of the Seas.

For months, the 250,800-ton ship, which can carry almost 8,000 people, has been in the headlines, including some who have criticized its size and potential to harm the environment. But passengers who spent between $1,800 and $100,000 and boarded the ship in Port Miami, Florida, on Jan. 27 said nothing could have prepared them for the ship’s magnitude.

“It’s impressive,” said Christina Carvalho, a 43-year-old accountant from Oakland, California, as she stood on the ship’s Royal Promenade, gawking at “The Pearl,” a giant kinetic art installation. “It feels even bigger than I expected.”

While Royal Caribbean has filled the ship with amenities to create “the ultimate family vacation,” the company’s design team has sought to challenge negative stereotypes like crowded decks and long lines. Instead of steel walls, the interior is open and airy, with floor-to-ceiling windows to bring passengers closer to the water and make the central thoroughfare feel less like a shopping mall.

“Over the years, our customers told us that even though they were in the ocean, they didn’t feel connected to it, so with Icon we wanted to bring water everywhere,” said Jennifer Goswami, director of product development at Royal Caribbean International.

I was aboard the Icon of the Seas for five days of her seven-night inaugural sailing to the Eastern Caribbean. These are some of my conclusions:

Boarding begins through the Royal Caribbean app. After a few glitches, it took me 10 minutes to scan identification documents, fill out a health form, and choose a time for boarding.

On the day of the trip, I headed to Port Miami expecting chaos, but when I got out of the taxi, I was greeted by a porter who took my bag and walked me to the terminal. I scanned my app, showed my passport and went through security in less than 10 minutes. I lingered, waiting to see if others had as smooth an experience as mine, but there was just a steady stream of passengers coming up the gangplank.

The ship has the feel of a city, with eight distinct “neighborhoods.” My favorite, Central Park, was filled with 20,000 species of plants; It was the perfect place to walk or read on a bench. The Royal Promenade, with karaoke and piano bar, could get crowded and noisy at peak times.

The seven pools are designed for different vibes and demographics: The Hideaway is an adults-only infinity pool, with DJ sets and cocktails; Another adult pool has an adjacent children’s pool. Throughout the ship there were many empty loungers for bathers.

On our first day at sea, I was so surprised by the relative absence of crowds that I walked around the ship trying to find them. But with so many venues, including 40 restaurants, bars and entertainment venues, passengers were constantly on the move.

Looking for a quiet space one afternoon, I found the Acuadomo, a quiet seating area with wraparound windows. The other passengers took a nap there.

From a sunrise surf simulator lesson to a late night dance at the nightclub, the ship seems to offer something for everyone, most of it free. The water park with six slides was a big attraction. One ride, the Crown’s Edge, isn’t free: Starting at $49, it launches you (with a harness) over the sea, leaving you dangling.

There is a gym, running track, basketball and soccer court, mini golf course, pickleball, rock climbing and dancing. A wellness center and spa offers treatments for an additional cost. Everything can be booked in the app; For popular attractions like Crown’s Edge it helps to book early because spots fill up quickly.

For evening entertainment, “Aqua Action” stood out, with aquatic performers performing under a 55-foot waterfall, as did the comedy club.

Not surprisingly, some passengers felt overscheduled. “There’s almost too much to do,” said Nancy Carter, 54, a nurse from Brighton, England. “It’s hard to plan your day and even when you’re busy doing something, you feel like you’re missing something else.”

In the Surfside neighborhood there are pools and restaurants for both adults and children so families can spend time together. For parents who want some alone time, Adventure Ocean Daycare has play areas and programs for ages 6 months to 12 years that are included in the rate.

There is also a teen social center with games and music. “It’s a great place to meet new people and make friends,” said Madison Foxx, 14, of Morrisville, North Carolina. Her mother, Ashley, a 38-year-old federal prosecutor, said the boat kept her two children entertained and allowed them both alone time and quality family time.

“I can relax and the kids are happy and busy all day,” she said. “So we have a lot of special moments together.”

One of the biggest surprises was the variety of dining options.

The Windjammer Cafe and main dining room were the busiest all-inclusive options. My daily go-to was the Aquadome food hall, with made-to-order crepes and a Greek food stand. Another favorite of mine was Pier 7, a restaurant in Surfside that served raw tuna Buddha bowls, mango-lime shrimp toast, and other dishes.

Meals at specialty restaurants, such as Giovanni’s Italian Kitchen and Hooked Seafood, cost extra or are included in some food and beverage packages ranging from $9.99 to $115 per day. Reservations are recommended.

The Empire Supper Club offers an eight-course meal accompanied by cocktails. For $200, the tasting menu included Wagyu prime rib, rabbit and sea bass with parsnip and red beet.

Cabin prices, which recently increased due to high demand, range from $2,699 per person for an indoor cabin to more than $100,000 for a three-story townhouse with an indoor slide and backyard. Some homestays have connecting rooms and large terraces.

Although it was only 204 square feet, my ocean balcony room didn’t feel crowded thanks to the minimalist design and views.

Royal Caribbean says it set a new standard for sustainability with this ship, installing advanced water and waste treatment systems, among other features. But some environmental groups say building a ship this size is not compatible with the cruise industry’s long-term sustainability goals.

On board, I saw staff sorting through trash to remove stray items for recycling, and single-use plastic seemed to be minimal; Passengers were provided with reusable cups at beverage stations.

I was taken by surprise that the water slides remained on, even after they were closed to riders. It seemed like an unnecessary waste of energy. (Royal Caribbean did not respond to a request for comment.)

Passengers I spoke to didn’t seem overly concerned about the ship’s potential to harm the environment, with some arguing that land and air travel aren’t climate friendly either.

Our seven-night itinerary began with two days at sea. The first stop was on the 4th in Basseterre, the capital of St. Kitts and Nevis. Excursions ranged from a hike up Mount Liamuiga to a food and rum tour, with prices ranging from $39 to $249. I chose a boating and snorkeling excursion ($155) and enjoyed the secluded bay, but the beach was crowded and touristy.

One excursion anticipated by Ms. Foxx, the federal prosecutor and others was Coco Cay, Royal Caribbean’s private island. When I asked about her visit (I called later because she had to disembark before the excursion), Mrs. Foxx said that her children loved the slides and snorkeling.

And would you sail on the Icon of the Seas again?

“Yes, but it could wait a little,” she replied. “I want everyone to have a chance to try it.”