• Astern – Toward the stern of a vessel, or behind the boat.
• Before the wind – Sailing with the wind from astern, in the same direction the wind is blowing.
• Lee – The side sheltered from the wind.
• Sheet – A line attached to the clew of a sail and is used to control the sail’s trim. The sheets are named after the sail, as in jib sheets and main sheet.
• SOG – Speed of ground. Actual boat speed over the ground using GPS.
• Stern – The aft part of a vessel. The back of the vessel.
• Working sheet – The sheet that is currently taught and in use to control a sail. The opposite of the lazy sheet.
• VMG – Velocity made good. Actual boat speed after adjusting for such factors as current and leeway.