On a recent cruise aboard a ship known for its sophisticated menus, I headed to dinner in the main dining room on the first night, anticipating spirited conversation at a table for eight. We would be four couples, strangers drawn from a list of international passengers on vacation in the South Pacific.

Half the diners at my table never showed up that night — or the next.

“My husband didn’t want to get dressed up, so we ate at the Lido buffet,” said a woman from Hawaii who appeared with her husband, traveling tieless, on evening No. 3. The fourth couple remained absent for the entire cruise.

According to the Celebrity Century hotel manager, second seating in the main dining room was the least popular dinner choice on the ship.

Declining to dress and linger over dinner is a growing trend, and cruise lines are reacting by providing more casual dining choices in their main and alternative restaurants. It’s a change that fits well with another vacation trend that is tied to the eating habits of busy North Americans — a demand for more comfort food.

You could it a re-hamburgerization at sea — with flair.

Add snazzy pizzerias (Princess Cruises heads the pizza parade), deli sandwiches and hotdogs (Royal Caribbean leads the way) and a mix of Mexican dishes (Carnival is introducing a Cantina), and what you get is an array of cruise eating choices similar to restaurants at home. More homey, upscale Celebrity has a backyard barbeque for do-it yourself grilled steaks on its two newest ships, including the Reflection, coming out this fall and arriving in Miami in December.

In the ebb and flow of consumer tastes over the past four decades, I have watched passengers and ships change dramatically, particularly on the bigger mass-marketed vessels. At first, the ships grew more sophisticated as cruise lines — especially Carnival — moved from hamburger-and-hotdog environments in the 1970s to something approaching your favorite restaurant at home for special occasions.

By the 1990s, most cruises were an opportunity to dress up, perhaps rent a tux. Each evening, passengers paraded through the main dining room in the latest cruise wear.

Now, the burgers and dogs are back. And passengers in shorts, T-shirts and flip-flops, surprised to learn that their attire is slightly below minimum standards in the main dining rooms, head to the Lido for a buffet dinner.

While the fanciest luxury ships have retained much of their formality, and traditional lines such as Celebrity, Oceania and Holland America continue to point to their main dining rooms as culinary showcases, most mass marketed ships have moved their emphasis elsewhere, or, at the least, have dressed down their menus and clothing requirements.

Gone are the formal nights; even on most of the best ships, a man can leave his tie at home. And gone, too, are the fancy-schmantzy menus and tiptop service in many of the main dining rooms. Today, partly as a result of cruise ship rates remaining low while operating costs rise, if you want a special meal you will book a table outside the main dining room at an alternative restaurant and pay an extra fee for dinner — $20 to $40 each for the more gourmet choices (which nearly always are worth the cost).

Norwegian, the industry leader in the cruise dining revolution toward eating what you want, when you want, offers so many choices that you can skip the main dining room entirely — a concept reinforced on its newest ship, the Epic, where there is no main dining room. While a majority of the restaurants on Norwegian ships carry extra fees, you could eat plenty of comfort food for a week at eateries that carry no extra charge.

Carnival Cruise Lines has bucked the industry trend toward adding alternative restaurants at a fee — only its Steakhouse ($30) and a new Italian eatery on Carnival Magic ($12) charge extra — and is expanding its free dining choices as part of new Fun Ship upgrades in comfort food categories such as burgers, tacos and burritos.

Just five years ago, Carnival’s celebrity chef, Georges Blanc, trained ships’ master chefs in France and added special Blanc items to each night’s menu. Today, Blanc is gone, the main menus are similar to what you would see in American restaurants, and Carnival’s new celebrity chef is Guy Fieri, who is known for his hamburgers. Guy’s Burger Joint debuted on Carnival Liberty and soon will be in the Lido of several other Carnival ships.

Meanwhile, back on Celebrity Century in the South Pacific, I happened upon the tieless husband from Hawaii roaming the ship at midday. What did he recommend for lunch? No doubt, he said, the best choice by far was a burger cooked on a grill outside by the pool.

David Molyneaux writes monthly about cruising. He is editor of TheTravelMavens.com