Watercraft is any vehicle designed to travel on or through water. The word covers everything from a simple wooden canoe paddled across a calm lake to massive cruise ships carrying thousands of passengers across oceans. A kayak is a watercraft, and so is a speedboat, a sailboat, a submarine, and even a surfboard.

The term is especially useful when you need to talk about water vehicles in general without specifying exactly what type. A sign at a beach might say “No motorized watercraft allowed,” meaning no jet skis, motorboats, or anything else with an engine. A marina rents out various types of watercraft for people who want to explore the harbor.

Unlike “boat” or “ship,” which suggest specific sizes or shapes, watercraft can describe anything that floats and moves purposefully through water. Ancient people hollowed out logs to create simple watercraft for fishing and travel. Today, engineers design watercraft for racing, exploration, transportation, recreation, and military operations. Whether it's propelled by paddles, sails, motors, or nuclear reactors, if it carries people or cargo across water, it's a watercraft.