An ancient warship propelled by three banks of oars; respectively the top, middle, and lower banks had two, two, and one (i.e., 5 total) men per oar Royal Mail Ship Any ship carrying mail for the British Royal Mail, allocated ship prefix RMS while doing so.
A keelboat is a riverine cargo-capable working boat, or a small- to mid-sized recreational sailing yacht. The boats in the first category have shallow structural keels, and are nearly flat-bottomed and often used leeboards if forced in open water, while modern recreational keelboats have prominent fixed fin keels, and considerable draft.
Mast Configuration and Sails Catboat (one mast, one sail) Cat A cat rig has only one sail, and the mast is located well forward. This is a popular rig on smaller boats, which are known as "catboats." This is the easiest sail plan to sail. Sloop (one mast, two sails) Sloop The most common type of sailboat is a sloop. A sloop has one mast and two sails, a mainsail and a headsail.