Cruise ships have a reputation for encouraging a measure of gluttony.

On nearly every modern ship, you may start eating before the sun comes up and maintain a forkful until late into the night, when a call to room service will bring a snack to tide you over until dawn. A cruise can be a constant flow of French fries, sticky buns, and globs of multi-course meals with a never-ending supply of desserts and between-meal enticements.

Eating full, of course, is not the same as eating well.

When an expert travel agent described Oceania Cruises’ newer vessels — the upscale Marina and Riviera — as the “eating ships,” he wasn’t talking about passengers stuffing themselves from plates piled high. Instead, he was describing meals at sea that rival the quality of your favorite restaurants at home — all included in the basic cruise rate.

This is a formula that is working well for Oceania Cruises, which is branding its ships as floating country clubs with a host of chefs who draw the biggest applause from passengers at gatherings of ship personnel.

On Oceania, the chefs are the artists whose presentations vacationers come to taste.

Before I get to the unlimited lobster tails and lamb chops on the Riviera during a recent Caribbean voyage, let’s look at what you get for your money on one of the so-called premium cruise lines:

The cruise industry has three basic rankings for ships — contemporary (or budget), premium (or pay a little more) and luxury (with daily rates that reach my monthly rent).

Lines between the categories have blurred, especially among the bigger ships. For instance, contemporary cruise companies such as Royal Caribbean and Norwegian keep adding intriguing activities and new restaurant choices to raise the value of their products (and their rates) in competition with large ships operated by premium lines such as Princess, Celebrity and Holland America.

Complicating the issue is the trend toward charging extra for some activities and for meals at specialty restaurants, which are at least a cut above the fare in main dining rooms, where food is included in the basic rate. The result is that you may have premium experiences aboard a budget ship by paying extra fees. These days, a cruise that started at $100 per person per night easily can become $200 a night.

When comparing ships of different categories, such as contemporary and premium, two major differences stand out — the quality of service and the public spaces available for relaxing, reading, and talking to new friends.

On contemporary ships, cruise lines seem to be shoe-horning as many people aboard as they can get away with (for obvious financial reasons), which is why buffet lines are crowded and you probably won’t see much of your busy cabin attendants or table waiters.

So, if you book one of the contemporary ships, upgrade to a higher-priced cabin and take advantage of some fee-based accoutrements, you may pay as much for your cruise as you would pay on a premium ship that has a larger, better trained staff and public rooms with an atmosphere of more elegance and comfort.

Such differences can be significant on the best of the smaller premium ships — some call them upper premium — operated by Windstar, with three (soon to be six) ships of approximately 200-300 passengers; Azamara, with two nearly 700-passenger ships; and Oceania, with five ships that range from about 700 passengers to the newest 1,250-passenger Marina and Riviera.