I've sailed oceans, rivers and the Great Lakes. Here's the difference.

• Ocean cruises provide a wide range of ship sizes, destinations, and onboard amenities.
• River cruises feature smaller, boutique-style vessels that often dock in the heart of cities.
• Great Lakes cruises utilize smaller ships for port-intensive itineraries similar to river cruising.

In the final hours of my visit to Milwaukee, I rushed to fit in one last destination.

My Victory Cruise Lines ship had stopped in the Wisconsin city for a day during a cruise through the Great Lakes. I explored earlier in the day and had reboarded the ship. But as our 8 p.m. departure approached, I took a brisk walk to grab dinner at Milwaukee Public Market. I had missed it when I was out before, and it was only about 20 minutes away on foot.

I ordered a Thai rice bowl from Forage Kitchen and a snickerdoodle for the road from C. Adam’s Bakery and made it back onboard the Victory I ship with 45 minutes to spare. The ease of getting on and off the 190-guest vessel, combined with walkability to Milwaukee’s Historic Third Ward and the late departure, made bonus sightseeing possible, something that would have been more challenging on many ocean cruises.

The kind of cruise experience guests have can depend in large part on the type of waterway they choose, with significant variety among lake, ocean and river itineraries. Here are some key differences between the ocean, river and lakes cruising.

Ocean: Options for every type of traveler

Ocean cruising is defined by a vast spectrum of cruise lines and ship types. Those range from small ships carrying roughly 100 people to mega-ships with 7,000 or 8,000 guests, according to Gary Smith, owner and CEO of TravelPerks.

Destinations range from staples like the Caribbean, Mediterranean and Alaska to less-visited locales like Antarctica and the Galápagos Islands. Itineraries may serve as three-night weekend getaways or last for months on cruises that visit multiple continents.

Travelers can choose from luxury lines like Silversea Cruises or Regent Seven Seas Cruises with a more “spa-like” onboard atmosphere, Smith said, or family-focused operators like Royal Caribbean and Carnival Cruise Line with a plethora of onboard activities from ice skating rinks to roller coasters – and many brands in between.

“As the ships get bigger, really, the ship becomes part of the destination, if not actually the primary destination for what you're going to see and do, because of the entertainment, the ‘wow’ features,” he said. 

Ocean cruises often bundle less with their base fares than other types of voyages – though that can also vary significantly by cruise line. Big-ship mainstream brands, for example, tend to charge extra for alcoholic drinks, shore excursions, Wi-Fi and other amenities, while luxury brands have more inclusive pricing structures.

River: A 'floating boutique hotel'

River vessels have little in common with the flashy mega-ships that define much of modern ocean cruising. “Honestly, I consider it just a floating boutique hotel, where I don't have to unpack as much,” Smith said.

Capacities often range from 160 to 190 passengers, and the “spectrum from low-end to high-end is very narrow,” he added. River ships sailing in Europe, among the most popular destinations for those types of cruises, are generally designed to be as large as possible while fitting through the necessary locks along the waterways.

“It's not a question of the size of the ship at all,” he said of the distinctions between brands. “It's really a question of what that company (has) chosen to do inside the box.” Some allot space for more guests and forgo amenities like gyms and spas, while others offer those with a lower guest count.

River cruise base fares typically include beer and wine with dinner and at least one excursion in each port (though specifics vary by cruise line).

“The Danube, the Rhine, any of the major rivers … you're almost always docking right down where you need to be, walking distance,” he said. “I mean, at worst, they'll provide a small shuttle or tour bus.” There are also more rural rivers, such as the Douro.

Even on a Viking Mississippi cruise I took in December, low water during our planned visit to Vicksburg meant the ship had to stop at an alternate landing outside of town. However, the cruise line offered complimentary shuttle rides to and from the shops, museums and cafes along the city’s Washington Street, just 20 minutes away.

Viking is a major player in the river cruise game, along with operators such as AmaWaterways, Avalon Waterways and Uniworld Boutique River Cruises. Celebrity Cruises will also launch river cruises for the first time in 2027.

Great Lakes

Great Lakes ships tend to be on the smaller side, too, with “only a couple hundred people in general,” Smith said.

Cruise lines operating there include Victory, Viking, Pearl Seas Cruises and – beginning this year – its sister brand, American Cruise Lines, which offers a variety of ship types and accommodations. Typically, itineraries range from shorter journeys lasting about a week that “can be a little bit more nature-oriented and not the city-oriented version,” Smith said, or more expansive voyages lasting up to 15 days.

My itinerary with Victory – which also sails along the East Coast and in the Canadian Maritimes – lasted nine nights from Chicago to Toronto. Stops included major cities like Milwaukee and Detroit, along with smaller destinations such as Mackinac Island in Michigan and Canada’s Port Colborne, the latter of which offered access to nearby Niagara Falls.

“The experience is very akin to a river ship, in that it is more inclusive,” Smith said. “I don't want to say (it’s a) slower pace, because what most people get wrong about river cruising is that they think it's somehow relaxing, when actually, you know, it's active as heck.”

My cruise was port-intensive with just one day at “sea” – on Lake Huron – and with multiple excursions on offer in each place. Guests could also explore on their own, and I took or surpassed 10,000 steps most days of my sailing.

This story was updated to refresh headlines.

Nathan Diller is a consumer travel reporter for USA TODAY based in Nashville. You can reach him at [email protected].