Navigating the World of Downwind Sails: Your Reaching and Running Inventory

October 16, 2024

Quantum's specialty line of high-performing downwind reaching and running sails are versatile, easy to trim, and tailored to the unique characteristics of your boat and your type of sailing. They're designed to help you get the most out of your experience and your time on the water.

From Code Zeros to Spinnakers, we have the run down from Jason Currie — Quantum's Mid-Atlantic Regional Manager based in our Annapolis Loft.

YOUR BOAT

A boat's design greatly impacts which downwind sail option suits each sailor. For more traditional cruising boats with small foretriangles and overlapping headsails, reaching angles are often served by a large genoa. An A2 or A3 rounds out your sail inventory to cover the broader angles.

On the other hand, modern boat designs tend toward larger foretriangles with non-overlapping jibs. These smaller headsails lack the punch of their larger genoa cousins when reaching. AWA 40, 60, or 80 reaching sails fill this gap. Some other questions to address when determining your boat's best sail options: Bowsprit or not? Mono or multihull? Is your priority performance or ease of handling? "A good amount of the decision-making is to do with the area you're located and the type of sailing you're doing," adds Currie. "Someone sailing in San Francisco Bay is likely looking for something completely different than someone sailing on Chesapeake Bay."

Quantum's experts can help you sort these and other questions to make sure you get the perfect downwind sail option for you and your goals.

TYPES OF SAILS

Reaching Sails

Sometimes referred to as "code zeros" or "code sails," the category of reaching sails gets confusing quickly as the term can apply to a broad range of sails. Quantum developed its line of reaching sails around the target apparent wind angles to simplify and clear up any confusion. After all, this is how we actually sail!

"In terms of geometry, the triangle of the luff, leech, and foot are oftentimes very similar, the biggest difference is the mid-girth — the measurement across the sail," says Currie. "Sails with a smaller mid girth are designed flatter, which makes that sail more of a tight reaching/screecher type sail – we see that a lot on cruising catamarans."

"Conversely, an AWA 80 has a much bigger mid girth, so a sailmaker must add more shape to support that length, which also adds depth and sail area," he continues. "This allows for broader reaching angles off the beam and aft quarter and is more for someone looking to get good downwind VMG performance."

Our three sail options are defined by possible apparent wind angle and overall optimum range. Each reaching sail line is available with a traditional torsional cable or as an XC cableless sail with a structured luff.

In summary, an AWA 60 is a split between the AWA 40 and AWA 80, and is more of an all-purpose code zero with the traditional midgirth. "It's the most popular one I and the majority of our team sell because it covers most ranges without being specific to one angle range," says Currie.

Cable vs Cable-less

A good place to start with the debate: "Generally, cable code zeros are for cruisers, and racers often go for the cableless option," says Currie. In addition, if your boat has a top-down furling unit, your only option is a sail with a cable."

Now that we have that out of the way, Currie continues: "The difference in sail design. A cable-less design lets us push the luff of the sail forward, so when you're sailing on a broad angle downwind and you ease the sheet, the sail can project further out front  [5 to 10 degrees]. With the cable, you can't go that far. More luff projection with cable-less sails adds a little extra performance.

The superior racing performance is a result of a straighter, more stable leech, and a flatter exit, both contributing to an increase in drive in all conditions but not overpowering the boat in heavy-air reaching. And with a more balanced mid girth, there is less backwinding of the mainsail, which creates less drag when sailing tighter angles.

Quantum's XC structured luff technology and designs are great for reaching applications like the AWA 40, 60, and 80. They are available in membrane or tri-radial construction to meet the needs of any sailor.

Running Sails

Downwind sails fall into two categories: reaching and running. For broad angles, Quantum's line of spinnakers fits the bill. Quantum's A3 is an all-purpose asymmetrical spinnaker and covers the mid-range, while the A2 is designed specifically for broad-reaching and running performance.

"The A3 is going to be a smaller sail," explains Currie. "You'd slot the A3 between the AWA 80 and the A2 in terms of sail area."

For the customer who would rather not carry a Code Zero, these are great options. "Usually, I'll suggest an A2 as a solid downwind sail," explains Currie. "But, it does depend on location. For some sailors, the A3 could be a better sail in a windier location, as it's slightly smaller and a little safer as far as not overpowering the boat if the breeze is up." As always, the best bet is to chat with your Quantum rep about the type of sailing you'll be doing and what might be the best fit.

MATERIALS

For more traditional asymmetrical spinnaker sails such as the A3 and A2, nylon continues to be the best material. "If you're a cruiser, we generally suggest one of the two spinnaker fabrics: 3/4 ounce nylon or 1.5-ounce nylon, depending on the size of the boat and sail," Currie explains.  "Generally, for a boat up to 40 feet, we do 3/4 ounce nylon, and you're good to go. Plus, these fabrics come in a variety of colors which can be fun to design." For racing spinnakers, most sailmakers will choose polyesters, or different nylons in weights from 1/2 ounce to 1.1 ounces.

Nylon is not necessarily the best choice for the new generation of specialized reaching sails — a stronger material is required to handle higher loads at closer apparent wind angles, and composite materials or Dyneema fibers tend to fit the bill. "There are nearly endless options, between durability and weight of fibers," says Currie. "The stronger the fiber, the better the sail will do in holding its design shape. But, that can come with added cost, weight, or other performance factors."

Quantum's proprietary Fusion M tri-radial construction process is used to create the ultimate custom structure for membrane reaching sails. Quantum collaborated with industry leaders to develop a range of composite materials specifically for high-load reaching sail applications.

STORAGE

Bottom-up furling

Bottom-up furling systems work in a similar way as conventional headsail roller furling systems. The tack of the sail is connected to the torsion cable which is fixed to the drum. As the drum turns, the sail furls around the cable or the structured part of the luff instead of an aluminum foil. The sail furls from bottom to top. Bottom-up units are a great option for the AWA 40 and 60 reaching sails, as the top of the sail is not too wide. The mid-girth is generally between 50 - 70%.

Top-Down Furling

As downwind sails get bigger and the mid-girth increases, it becomes harder to get the top of the sail to furl if you start from the bottom. With top-down furlers, the tack is secured to a free-rotating fitting on the drum. As the furling line is pulled, the cable furls to the top before the tack, and the sail rolls from head to the tack, capturing the hard-to-furl top sections first.

As always, in sailing there is no one-size-fits-all solution to the best sail or sail material for your boat. At Quantum, our experts take the time to understand the type of sailing and conditions you generally experience, any performance challenges you want to resolve, and budget to come up with the perfect sail solution, together with our customers. Reach out to your local Loft to start the conversation.