Sometimes, you will use your ship as nothing more than a home base from which to explore ports of call. In other cases, your ship will be a destination unto itself — bigger and more packed with activities than some of the towns where it will dock. And in both cases, whether you want to be aboard a mammoth vessel or within a cozier setting, you can have either top-shelf luxury or more affordable amenities. There are big ships and small ships, luxurious ships and value brands, in multiple combinations.