 The foremast and mainmast are both square-rigged, but the fore and aft rigged spanker sail is attached to a small trysail mast (or in modern times a steel cable) stepped directly behind the mainmast.This "snow-mast" allows the gaff to raised unhindered by the mainmast and higher than the main yard, which in turn also allows the snow to fly a main course without complications.Three masts or more, square rigged on all except the aftmost mast.