The term, pinnace can refer to a boat or a ship.
(1) A pinnace was a small boat used in various navies as a ship's boat - for carrying officers ashore for example. Its size depended on the size of the warship. In the Royal Navy it was smaller than a ship’s “launch”. In the German and French navies it was the second biggest ship’s boat. Most could set some sort of simple mast and sail rig. There were the makings - a sort of "flat pack" - of a pinnace on board Francis Drake's "Golden Hind" which was "commissioned" when the venture reached the Pacific. Armed with a few small cannon, it became the galleon's attack dog.
(2) A pinnace was a small 3-masted armed ship in the 16th and 17th centuries, originally of about 18 guns but later up to about 40. In its duties it was the fore-runner of the frigate. It tended to have a relatively high stern-castle, sometimes ornately decorated. It had two square-rigged sails on each of its two forward masts, and a lateen sail on the mizzen, with a square sail above it. The bowsprit also sported a small square sail on a tiny mast.
Large pinnaces, as armed cargo vessels, made up the bulk of the Dutch East India Company’s fleet during the period of its ascendency in the East Indian trade.
- Square-rigged refers to the set of the sails on what most people would consider the classic large sailing ship – the galleon or the clipper for example, or any large warship of the age of sail. The sails are set across the bow to stern line of the vessel and are four-sided and attached to yards that can be angled according wind direction. (Very few vessels in the last 500 years have been purely square-rigged – almost every ship has had triangular staysails set between the masts or from the foremast to the bow and most have a gaff-sail on its stern-most mast – usually called a “spanker” – whether or not there is square rigging on that mast.)
- Mizzen refers to the aft mast. The one at the stern.
- Bowsprit. The boom projecting from the bow of a sailing vessel to which can be attached the forestaysails, also known as headsails, the leading one of which is referred to as the jib. Sometimes, during the Age of Exploration and after, a square-rigged sail would be set from it, or even from a tiny mast on it.
Reference: "The Oxford Companion to Ships and the Sea."