Cat rig
A single mast stepped near the bow carrying one large sail and no headsail.
A cat rig has one sail on a mast stepped well forward, with no jib. On the Nonsuch series the mast is unstayed carbon or aluminium and the sail is controlled by a wishbone boom, which makes the boat exceptionally simple to sail single-handed: there are no sheets to change when tacking and no standing rigging to inspect or replace. The large single sail must be reefed early, and the unstayed mast is a specialist item if it ever needs replacing.