2 min read · Updated 19 May 2026
The A2 is a yacht's all-purpose running asymmetric spinnaker — a full, powerful, light-to-medium-air sail flown deep downwind to make the best speed towards a leeward mark. If a boat has one go-to spinnaker, it is usually the A2, and it is the workhorse of the downwind sail wardrobe, sitting one step deeper than the reaching A1.
What the A2 does
Downwind, the goal is not simply to point at the mark and sail straight there. A yacht is much faster on a broad reach than dead downwind, so crews sail a series of broader angles and gybe between them to make the best progress towards the mark — a balance measured as velocity made good, or VMG. The A2 is the sail built for exactly that job: a deep, full asymmetric that generates maximum power at the running angles where VMG is won.
Cut fuller than the reaching sails and made from light cloth, the A2 fills and pulls in soft to moderate breeze and keeps the boat driving deep. It is the sail a crew sets at the windward mark for the run, and the one they work hardest to keep flying fast and stable.
Where the A2 sits
In the standard naming system, even numbers are running sails, so the A2 is the light-to-medium running spinnaker. Its neighbours are the flatter reaching A1 for tighter angles and, as the breeze builds, the heavier reaching A3 and running A4.
On a planing boat like the Melges 40, the dynamic shifts: with enough breeze the boat sails fast on hotter angles and gybes through bigger arcs, so the running sail is flown actively and trimmed constantly. Setting and dropping it cleanly at the marks is its own discipline, covered in spinnaker hoists and drops. For the whole inventory and how these sails are built, see the sails pillar; for the boat that flies a roughly 200-square-metre gennaker, the boat page.
Frequently asked questions
- What is an A2 spinnaker?
- The A2 is an all-purpose running asymmetric spinnaker, used in light to medium air on deeper downwind angles. In the standard naming system even numbers are running sails, so the A2 is the workhorse downwind sail — full and powerful, cut to drive the boat deep towards a leeward mark rather than to reach across the wind.
- What is the difference between an A1 and an A2?
- The A1 is a flatter reaching spinnaker for tighter, closer angles, while the A2 is a fuller running spinnaker for deeper angles. Both are light-air sails, but the A1 powers the boat up on a reach and the A2 drives it downwind, so crews switch between them as the course and angle change.
- What does sailing for VMG downwind mean?
- Velocity made good (VMG) downwind is the speed a boat makes directly towards a leeward mark, not just its speed through the water. Because a yacht is faster on a broad reach than dead downwind, crews sail a series of angles and gybes with a running sail like the A2 to maximise progress towards the mark, even though the straight-line distance is longer.