ASYMMETRICAL SPINNAKERS
A1 Light Air Reacher — VMG Spinnaker
Maximize downwind speed in light conditions with our radial Matrix construction A1. Designed for apparent wind angles 70–110° and 0–10 knots, this high-performance spinnaker delivers flat entry for better VMG and reduced distortion for consistent power.
Why choose an A1 Light Air Reacher?
In winds under eight knots true, boats make the best progress sailing with apparent wind around 90-degrees and then jibing. The A1 Light Air Reacher (also known as the VMG spinnaker) is specifically designed for these conditions, and is typically made from .5 to .6 oz. high performance nylon like Airx or Superkote. It features a flat entry for sailing closer to the wind and reduced area to make it easier to fill in light winds.
Optimized for VMG
Flat entry for tighter angles
Designed for apparent wind angles 70-110°, the flat entry allows you to sail closer to the wind while maintaining optimal downwind velocity made good in 0-10 knot conditions.
Matrix Construction
Radial panel layout
UK’s Matrix construction features narrow panels oriented to align cloth threads with primary loadpaths, creating the strongest sail for its weight while minimizing distortion.
High-Performance Materials
Premium nylon
Built from .5-.6 oz performance nylon that has the strength and stretch resistance of one weight heavier standard nylon, preventing distortion and maintaining shape.
Understanding Matrix Construction
The key to faster spinnakers lies in their construction. UK Sailmakers uses a Matrix panel layout—a radial design made up of narrow panels aligned with the sail’s primary load paths. Panels radiate from the head, tack, and clew, joined by vertical Matrix panels through the midsection. This layout minimizes distortion and delivers the strongest, most efficient sail for its weight.
Each panel is shaped on all sides to create a smooth, round sail. To perform across a wide range of angles, a spinnaker must hold its designed shape without distortion. Distortion is most noticeable when close reaching. Spinnakers made from generic nylon tend to stretch through the middle, which causes the leeches to harden or hook. This reduces driving power, increases drag, and adds heel. The most effective way to prevent distortion, without using a heavier fabric, is to build the sail from performance nylon spinnaker cloth. These materials provide the strength and stretch resistance of standard nylon that is one weight heavier.
FAQs
What is the difference between an A1 and other asymmetrical spinnakers?
The A1 Light Air Reacher has a mid-girth of approximately 90% of the foot length, making it flatter than running spinnakers. It’s optimized for apparent wind angles of 70-110° in 0-10 knots, ideal for VMG sailing downwind.
What is Matrix construction and why does it matter?
Matrix is UK’s full radial panel layout with narrow panels oriented to align cloth threads with primary loadpaths. This minimizes distortion, especially when close reaching, and creates the strongest sail for its weight.
Can I use the A1 for racing and cruising?
Absolutely. The A1 is particularly effective for racing in light air VMG conditions, but its flat entry and easy-filling characteristics make it versatile for cruising as well, especially on coastal passages with lighter winds.
What’s the advantage of Airx or Superkote over standard nylon?
These high-performance nylon materials have the strength and stretch resistance of one weight heavier standard nylon, preventing mid-sail distortion that causes leeches to harden or hook—which reduces power and increases drag.
