Most of the trade cards having a nautical theme were for steam ships that crossed the Atlantic or carried passengers to and from East Coast resorts. The backs of transatlantic cards usually described the ships and their accomodations for the various passenger classes, while the backs of resort cards usually gave schedules and the kinds of entertainment that were available.
Another type of card having a nautical theme were the clipper ship cards issued by dispatch lines to advertise specific voyages of clipper ships from one port (usually New York or Boston) to another (usually San Francisco). They were distributed primarily during the late 1850s and early 1860s.. These cards are quite scarce, and none are shown here. However, the article Clipper Ship Cards by Bruce Roberts in the Articles About Trade Cards section describes these cards and provides several examples.
Some examples of trade cards with nautical themes are shown here at 25 percent of actual size. Click on a card for a larger view and a description that includes the price it brought at auction (without buyer's premium).