A gigantic vessel that carries 3,000 to 6,000 passengers is a destination unto itself, and some passengers don't even leave the ship while it's in port. But with smaller ships, offshore experiences are much more important than onboard entertainment, restaurants, and activities. The focus is on smaller geographic areas that can be explored in depth. Imagine a canal cruise across the Swedish heartland, a catamaran around the Galapagos Islands, or a small ship along Norway's fjords and coastal villages. 

There are certain itineraries — namely the Greek isles, Mediterranean, and Galapagos — where daily port calls are the norm, meaning you get to spend more time on land than at sea. You can maximize your sightseeing even more by choosing a line that includes overnights in port as well. Azamara's cruises all include a special evening event, from dinner at a Tuscan castle to a night at the symphony in St. Petersburg. The line also introduced a new Nights and Cool Places program, where for an additional fee you can do an evening, small-group shore excursion (like an after-hours visit to a museum). Silversea recently added overnights in some Italian and French ports, as well as later departures from hot-spots like Portofino and Amsterdam. Crystal Symphony's 13-day cruise from Singapore to Hong Kong includes overnights in those two ports, as well as a mid-cruise overnight in Ho Chi Minh City.

A cruise that hugs the coastline of one country, such as Japan, Italy, or Spain, will give you a richer experience. You can experience natural sites — beaches, gardens, volcanoes — as well as historical ones like ancient ruins, exotic temples, and magnificent cathedrals.

Onboard talks by experts can really enhance your connection with a destination — whether it's about the area's history, art scene, or flora and fauna. Cunard, Crystal, Silversea, and Lindblad Expeditions feature lineups of lecturers — from naturalists and scientists to authors and diplomats — who hold seminars throughout the cruise about the destinations and other topics, including politics and the arts. They also mingle with guests and answer questions, which can further deepen your knowledge of a destination.

In some regions, places of interest are near the port where the ship docks — think Barcelona, Venice, Naples, Stockholm, and most of the Caribbean — so you'll have more time to explore your destination. But in other areas, sites may be hours away from port via bus or taxi (Florence, Italy; Hanoi, Vietnam; and Bangkok, Thailand), which just means more time in traffic and less in the place you actually want to be.