Uniforms for naval officers—their cut, color, and adornments specified by regulation—began appearing in the 18th century. Ordinary crew members had to wait about another century before they were similarly provided for, although navies were making available clothing of a simple, common pattern well before that.
In every ship, one boat provided a captain’s personal means of transport. It was called a gig. Over time, captains—especially successful or rich ones—took to decorating their gigs to suit their personal tastes and to make them unique (rather like people today customizing their cars). They also took to outfitting their gigs’ crews with special uniforms, with hats, jackets, jumpers, and trousers of their own designs and coloration, often a combination indicative of the ship’s name, as when the gig crew of HMS Caledonia (an ancient name for Scotland) wore tartans.
The mid-1800s saw the captain of one British warship outfit his gig crew with dark blue jackets decked out with large brass buttons and with white trousers. Unquestionably, it was a smart outfit, and it soon caught the eye of both other skippers and many ashore who cared about sartorial matters. It is still with us today, as a garment to be worn when one wishes to be casually dressed up, and it continues to be known by the name of that ship: HMS Blazer.