A Pirate Waistcoat be the single best item to help raise ye from the ranks of a lowly deck hand to the pirate officer, such as a bosun or quartermaster. Commonly called a vest in today's vocabulary. We have different waistcoats that be of a historical accurate design from the 1580 to the 1830's.
The sleeveless coat started out being called a jerkin during the Buccaneer era n' they were short in length. During the Golden Age of Piracy, they came to be called waistcoats,n' were long in length. At first they were very long, to the mid calf, n' then became shorter, to mid thigh. During the Late Pirate Era, they shortened again and became Wesket. In modern times we call it a vest.
King Charles II of England, Scotland and Ireland introduced the waistcoat as a part of correct dress during the Restoration of the British monarchy. When it be too hot to wear a frock coat, go with a pirate waistcoat, as it is much cooler n' ye can sword fight with one on. A waistcoat should be buttoned closed when wearing a frock coat, but ye can leave them unbuttoned when wearing them without a coat.