What is a 'ship'?Although many people often refer to anything larger than a rowboat as a 'ship', in fact for real sailors and pirates the term 'ship' applies only to vessels that meet certain criteria.
The classification of ships is usually based mostly on the configuration of their rigging.
To be called a ship the vessel must be square-rigged, and must have three full masts with at least three stages of sails - course, topsail and t'gallant. Any other vessel not meeting these criteria is a boat and is known by its class name - ie sloop, brig, xebec, etc. Creating one list that defines the different types of ships is difficult as, over the four or five centuries of the age of sail (and the Golden Age of Piracy itself covers some two centuries) the definitions of different classes of ships changed, some classes went out of use, and new classes came into use. The rating system for large warships described below, for example, only came into being relatively late, being used by the British Royal Navy from the late 1700s through the 1800s.
1st Rate: A ship of the line, the largest ship on the water at the time. Carries 100 great guns or more. Used by the established navies of the day. HMS Victory is a 1st rate. A great prize, but probably never used by a pirate since they required large crews (approx 800) and were expensive to operate:
2nd Rate: 90-98 gun ship of the line, next largest
3rd Rate: 64-80 gun ship of the line
4th Rate: 40-60 gun ship of the line.
5th Rate: 36 gun ship, as long as a first rate, but fewer cannons
6th Rate: 28-30 gun ship, also long and low. The HMS Surprise of "Master and Commander" fame was rated a 6th rate light frigate.
Frigate: Frigate encompasses a wide range of sizes from 4th to 6th rate. U.S.S Constitution is considered to be a frigate. This is probably the largest ship a pirate would have.
Schooner: Small class of ship, lightly armed carrying only 6 guns, well used for 300 years. Schooners come in both two-masted and three-masted varieties. But whether two or three-masted, schooners are fore-and-aft rigged. More common in the United States than elsewhere. Probably not a favoured ship
Sloop: ship type commonly used by pirates, had few guns, but a shallow draft, and was incredibly fast, great for negotiating shallow waterways, essential when running from pursuit. Jean Lafitte is known to have used these extensively. carried 20 guns on one gun deck
Corvette: Light and fast, corvettes were lightly armed (10 guns, though some did carry more), but more than made up for their lack of armament with their speed. Not known whether pirates used them, commonly given to privateers because of their speed. Also sometimes referred to as a "sloop-of-war".
Brig (and Brigantine): Small, fast two-masted ships. They took their name from the fact they were a favoured type of vessel for pirates or brigands. In earlier years brigantine referred to any small two-masted vessel that could be both sailed and rowed. Later the definition was more rigidly applied to certain rigging configurations. A brigantine is square-rigged on her foremast and upper mainmast, but her main sheet is actually rigged fore-and-aft on a gaff boom (as in the picture below). A brig is square-rigged on both masts. Carried around 10 guns
Barque (or Bark): The term 'barque' is one that has been in use in nautical terminology for a very long time, and has changed in definition over the years. Through the 1400s, 1500s and 1600s barque was usually applied to smaller coastal merchant vessels. In the 1700s the Royal Navy used the term generally to apply to vessels that did not fit into its other classifications. In the 1800s came to refer to a three masted vessel with a particular rigging configuration - square-rigged on the fore and main masts and fore-and-aft rigged on the mizzen.
Galleon: A class of ship developed and primarily used by the Spanish. Over several centuries galleons saw service both as merchant ships and warships. Galleons are large, heavy ships, broad in the beam, and usually characterized by high, multi-deck fore and aft castles. Those high structures, particularly the bulky fo'c'sles, tended to make galleons far less responsive in maneuverability. In later years the Spanish would cut down considerably on the size of the fo'c'sle in their galleon designs to improve performance handling, but they retained the high aft castles.
Below is an artistic rendering of a Spanish Galleon circa 1588 featuring the typical high fore and aft castles and low waist.
Image source: Konstam, A. "Spanish Galleon 1530-1690". Opsrey Publishing. Illustration by Tony Bryan
Galley: The ship of choice for pirates of the mediterranean. Galleys rely on banks of long oars, sometimes as many as two or three decks of rowers, as their primary means of propulsion. Although most galleys would have shipped at least one mast with sails as a backup. In smooth water conditions galleys actually tend to be faster and more maneuverable than sailing ships which makes them far superior in areas like the Mediterranean Sea. However they do not fare well in the rougher waters of the Atlantic or English Channel. Caribbean waters are somewhat more suited to galleys, but only somewhat. Sailing ships were still the vessel of choice there.
Fluyt: Fluyts were common in European waters and, given the presence of Dutch colonies in the new world and the trading activities of the Dutch East India Company, would have been no strangers in the waters patrolled by Caribbean pirates.
Merchantman: Another common type of vessel used by pirates. Encompasses a wide range of descriptions. These ships were built for carrying large amounts of heavy cargo, and were well built. Some merchantmen carried cannons, other did not, those that did carried large guns, and plenty of them. May be similar in size to a frigate, but certainly easier to take.
Gig: big rowboat.
Whaleboat: really big rowboat.
Dinghy: very small rowboat Fireship: floating molotov cocktail, might be made from any class of vessel.