HMS Jupiter was a 50-gun Portland-class fourth-rate ship of the Royal Navy. She served during the American War of Independence, the French Revolutionary Wars, and the Napoleonic Wars in a career that spanned thirty years. She was also one of the fastest ships in the Royal Navy as shown by her attempt to capture the cutter Eclipse under Nathaniel Fanning.

Copper sheathing is a method for protecting the hull of a wooden vessel from attack by shipworm, barnacles and other marine growth through the use of copper plates affixed to the surface of the hull, below the waterline. It was pioneered and developed by the Royal Navy during the 18th century. In antiquity, ancient Greeks used lead plates to protect the underwater hull.