A snow is a square-rigged sailing vessel featuring a foremast, a mainmast, and a smaller third mast stepped immediately behind the mainmast. This small mast, called the snow-mast, carries the spanker or trysail. The design allowed the vessel to carry a large fore-and-aft sail without the mast hoops interfering with the mainmast yards.
Heard on the job
The museum acquired a painting of a merchant snow entering the harbor.
Insider tip
The defining difference between a snow and a brig is that independent trysail mast.