The main difference between boats, yachts and ships is that boats have a length overall less than 197 feet; ships are 197 feet or longer; and yachts are pleasure, not commercial, vessels greater than 30 feet in length overall. Length overall measures the vessel's hull structure from end to end.
Boats, yachts and ships are conveyances or vessels that operate or float on the water. In nautical terms, boats are small craft. People use boats and ships for commercial, pleasure or residential purposes. Non-commercial and non-residential watercraft that are less than 30 feet in length overall are recreational boats or pleasure boats, not yachts. Yachts are moderately large vessels that people typically associate with luxury, elegance and wealth.