Headsails: Gennakers, Screechers and Reachers… Oh My!


Last Updated on April 1, 2021 by Amy

Figuring out what kind of sails your boat needs is not always a straight-forward and simple question.  All sailboats need sails, right?  But each sailboat may have a different set of needs.  Most cruising boats come standard with a small headsail and a mainsail.

The cruising route of 95% of circumnavigators is a downwind trade winds circumnavigation, which means we need to be set up for downwind sailing.  And while it would be quite nice, there is no one sail that a boat can use in all downwind situations.

Our previous catamaran (a Maine Cat 30) only had a self tacking jib.  This sail is small and doesn’t allow for a lot of adjustment, especially when going downwind.  We’ve chartered boats with larger genoas and I’ve done racing on beach cats with asymmetric spinnakers, but those setups are quite different from what we have on Starry Horizons.

Types of Headsails

For my own sanity, let’s take a look at the major categories of sails.

Sail Terminology

For those of you who may need a refresher of (or an introduction to!) sail terminology, hopefully this diagram will help.  Study it, memorize it, so that when you join us on Starry Horizons you’ll know what I mean when I say we need to attach the head of the sail to the halyard!


The jib is a headsail where the clew (bottom corner of the sail not attached to any standing rigging) does not come aft of the mast.  It can either be self tacking, like our previous boat, or use jib sheets running aft which are worked when the boat changes tacks.  These sails are typically on a furler, which means they can be reefed simply by rolling up the sail a bit.


Starry Horizons with her genoa.

Also referred to as the “genny”, this sail is very similar to a jib, except that the clew comes back aft of the mast and overlaps the mainsail.  Genoas are rated on a percentage, based on their area relative to the 100% foretriangle which is the area created by the forestay, the mast, and the deck.  Starry Horizons has a genoa from the factory, and its a great sail for downwind when the winds are high.

Spinnaker Introduction

Hold on to your hats ladies and gentlemen, cause this is where it gets complicated.  In general these sails are used for points of sail all the way from reaching to dead downwind, with some categories even capable of being used on a tight reach.  You may hear general terms such as a “kite” or “chute” being used in reference to spinnakers, and that’s because they somewhat look like a parachute out in front of the boat.  These sails are typically used in conjunction with a “sock” (aka snuffer) that makes deployment and retrieval relatively easy.  Some asymmetrics can even be fitting with a furling system, top down or regular, that will allow it to be furled similar to our genoa.

So now that we’ve covered the basics, let’s take a high level look down at the two main types of spinnakers, asymmetric and symmetric.

Asymmetric Spinnakers

These sails seem to be the most confusing as each sail maker can use different terms for the same sail.  Asymmetrics do seem to be separated by code from 0 – 6, which help classify them for racing purposes, but is helpful to differentiate among the sails.  Thanks to Wikipedia, here is a bit more about the code classification:

  • Code 0 The code 0 asymmetric is a tight reaching sail, the most upwind capable of the asymmetrics. The luff is as straight as possible, and the sail is flatter than other spinnakers. Due to the flatness of the code 0, it is usually made with a wire luff for strength, and of a heavier, less stretchy fabric than normal for a spinnaker. Due to the tight luff and flat cut, the code 0 can be fitted for roller furling.
  • Code 1 The code 1 is a light air reaching sail, where the apparent wind angle at low speeds has a significant effect to create angles of less than 90 degrees.
  • Code 2 The code 2 is a medium air running sail, used for apparent wind angles over 90 degrees.
  • Code 3 The code 3 is a medium air reaching sail, used for apparent wind angles near 90 degrees.
  • Code 4 The code 4 is a heavy air running sail, used in the heaviest winds normally expected.
  • Code 5 The code 5 is a heavy air reaching sail, used in the heaviest winds normally expected.
  • Code 6 The code 6 is a storm sail, for running in storm conditions.

Codes 1, 3, and 5 are reaching sails, and codes 2, 4, and 6 are running sails; the Code 0 is a hybrid of genoa and spinnaker, designed to work like a genoa but classified under racing rules as a spinnaker.  Clear yet?  Wait, it gets better.  North Sails has a line of sails called “gennakers” which are based off the Code 0 classification, while other manufacturers call their Code 0 sails “screechers” (for upwind use) or “reachers” (for downwind use).  Yeah, my head hurts too…

Starry Horizons has a bowsprit so that we can easily rig an asymmetric spinnaker.  Fountaine Pajot offers a gennaker as an option, and our dealer advised us that if we’re going to go with only one additional sail for our boat, that a Code 0 would be the way to go.  It was enough to make my head spin.

Symmetric Spinnaker

As you might guess from the name, these sails are symmetrical, and are typically stabilized using a spinnaker pole, which helps keep the sail on the proper side of the boat.  The beams on catamarans are wide enough that we wouldn’t need one.  In general, these sails are a bit trickier to use when shorthanded as you have additional lines that must be set, and the sail doesn’t seem all that forgiving, meaning it can dramatically open or close with gusts of wind, leading to nervous moments trying to handle the sail.


I’m throwing this one in here as its own category because I’m not quite sure where else to put it.  Parasailors and Wingakers are brand names of sails designed for short-handed sailing crews, seem extremely forgiving and have self-trimming features that would allow you to leave the autopilot on.  It definitely is interesting as a downwind sail, and could even be used to on dead downwind run.  I’ve found several blogs of people who have them, and they all seem to have high praise for the sail.  Pairing this with a Code 0 would give us a good variety of sails that could be used in all kinds of conditions.  The Parasailor uses a sock, which means we wouldn’t have to continually swap it out with the Code 0.  All in all, it’s a very intriguing option.

What We Have For Our Circumnavigation

We knew from the start that we were going to want to supplement the sails that come with a Helia and even chose the optional bowsprit and gear option from Fountaine Pajot in order to set up the boat for additional sails.  After lots of research, here is what we’ve decided on:

Top Down Furling

This was a decision we struggled with for a while.  The traditional way to set and douse a spinnaker is with a “sock” that slides up the sail as it’s being deployed and gets pulled back down over the sail in order to douse it.  This method requires someone to go forward on deck and can require some wrestling with the sail if the winds have picked up.  That’s not entirely ideal and part of the reason we like the Helia 44 so much is that almost all control lines are lead to the helm, meaning we don’t have to leave the helm in order to control the boat.

Our dealer introduced us to top down furling, which is used specifically for spinnakers.  Screechers (or Code 0’s) are flat enough that they can be furled normally.  Top down furlers are really unique systems that have a swivel attached to the furling drum at the tack of the sail, and a “torque rope”, designed to prevent twisting, that the sail actually furls around.  When pulling on the furling line, the swivel lets the tack of the sail swing free, while the head of sail begins to furl.  Eventually when there is enough tension on the sail, the tack of the sail will begin to furl as well.  It’s a bit tough to describe, so here is a video:

There are lots of different companies that offer these sort of systems, and we’re creating almost a ‘franken-rig’ combining favored components from each company.

Profurl:  We chose the Spinex Top-Down Spinnaker Furler with anti-twist cable to be the “torque rope” for our spinnaker.  This is a very interesting concept that allows the sail to furl faster and easier, as the bearings have a greater diameter than a typical rope, which also prevents the spinnaker from being wrapped too tightly.  As part of this, we also use the Profurl swivel, which can be used with our furling drum.

Karver: We went with a Karver KF2 Furling Drum.  This drum has a unique locking feature that will help prevent the sail from unfurling when we don’t want it to, which is kind of critical in my opinion.  We also rigged up some additional hardware to prevent this from happening, but more back up is always appreciated.  Another feature I really like is we can use the same drum with multiple sails simplifies sail changes and reduce costs.  All that’s need are separate torque ropes.


We worked with a Doyle sail loft that had a relationship with our dealer.  After determining which type of additional sails we wanted, I went around and got quotes from several different lofts.  It was a great learning experience in talking to all the different lofts, but in the end Doyle came in at the right price and has a great reputation as a sailmaker.


Starry Horizons with her screecher up.

This is a fairly all-purpose type sail.  It doesn’t fit in the traditional racing definition of a Code 0, but since Starry Horizons likely won’t be competing professionally anytime soon, that was okay with me.  The sail is 864 square feet, with a Tri Radial design, made from 5.5oz Dacron and has a white UV Dacron protective layer along the leech and foot.  There were additional options, such as a laminate material instead of Dacron, or square-weave Dacron, or even different weight Dacron, but I felt that the combination of a Tri-Radial design and the 5.5oz weight would give us a fairly good combination of sail performance and shape longevity.

Our contact at Doyle said we should be able to use this sail in light airs up to about 15 knots AWS (apparent wind speed) to keep things comfortable, and should be able to go from about 50 degrees AWA (apparent wind angle) to perhaps 120 degrees.  In real world use, we don’t go much higher than 55 AWA as we have to sheet the sail in so tight it rubs on the cap shroud.

Our fastest passages to date have been where we’ve used our screecher.  Ideally, for our highest speed performance, we sail at 90 degrees on the beam, with winds close to 15 knots.  We can average 200 nm days this way if the wind holds up.

Additionally, we’ve found this sail to be incredibly useful in more complex downwind sailing configurations.  We’ve used it to go wing on wing with our genoa and even moved the tack over to the windward bow to let us sail as deep as 145 degrees!

Asymmetric Spinnaker

For reaching and downwind performance, a spinnaker should be the way to go.  We chose to go with an asymmetric spinnaker, since it works with the top down furling system.  It also should allow for better reaching performance than a symmetric spinnaker.  Doyle calls our sail the Asymmetrical Power Cruiser, and it is made with Contender Nylite 90, a nylon-based fabric.  One of the cool (to us at least) features of this sail is that you get to choose from a rainbow of colors (with multiple colors and patterns being an option) and could also have a graphic inlaid in the sail.  It was very tempting to have the Starry Horizons logo put on, but in the end we decided to be true to the logo itself, and went for a dark blue spinnaker.

As for the performance of the sail, Doyle lists a range of 85-165 degrees AWA and 5-25 knots AWS.

All that being said, we’ve had a hard time with our spinnaker.  We’ve ripped it three times, one of the times pretty much in half.  The sail is very fickle and requires a close eye on it.

Additional Rigging

The Bowsprit and Gear package from Fountaine Pajot includes an additional winch on the port side of the cockpit to handle sheets, and we rearranged our winches in Palmetto to add an additional winch on the starboard side to make handling the sheets easier and clear up lines being lead to the helm across the deck.  I’ve drawn up a (really) rough diagram of how the rigging is run.

Rigging Diagram
Rigging Diagram

Continuous Furling Line: The line that fits around the furling drum that we use to furl in the sails.

Turning BlockTakes the furling line from the furling drum and redirects it down the side of the boat.

Harken Double Lead Turning Block
Harken Double Lead Turning Block

Ratchet Block: Used on the part of the continuous furling line that actually furls the sail, a ratchet block helps maintain tension on the line.

Harken Ratchet Block
Harken Ratchet Block

Stanchion Mounted Lead Block: Helps guide the furling line along the stanchions and reduces friction.

Harken Stanchion Mounted Lead Block
Harken Stanchion Mounted Lead Block

Stanchion Mounted CleatAllows for the furling line to be cleated off and prevent accidental deployment of the sails.

Winches: We have one on each side of the stern to control the sheet of the bigger headsails, which allows us to unfurl the sail, as well as control sail shape.

Harken Winch
Harken Winch

Pictures of Our New Sails

Before packing up the sails, the loft was kind enough to send us some pictures of the sails.

Asymmetric Spinnaker

This sail is 1,397 sq ft which means its bigger than my first two apartments.  That fact is what puts it in perspective for me.   You can see the furler in the picture of the tack, and that picture also gives a pretty good visual of the Spinex Sail Bearings.


The screecher is 864 sq feet, so it is not small by any means. Unlike the spinnaker with the Sail Bearings, the screecher has the torque rope sewn into the luff so it is a part of the sail itself.

Further Reading

Downwind Sail Configurations for a Cruising Catamaran

Planning a Route to Sail Around the World


  1. Several questions:

    What sail plan would you choose today if you had a Leopard 50?

    What do you know/think about Code D sails?

    I’ve been thinking of a Code D and a parasail but my mind is still open.

    Please help before I go insane!


  2. Just to get this off my chest, the thing I hate most about sailing is not the cost, the constant repairs, or having to be ready for anything. The thing I hate most is the repetitive and archaic lexicon that we must suffer. Thanks for another great article!

        1. We have an asymmetrical too down fueling spinnaker. It’s complicated to use, we’ve ripped it three times and we often pull it to the windward bow anyway.

  3. We chose the North no 5 asymmetrical in Contender Stormlite 250weight. We use a sock. Whilst it took a little bit to get a handle on it my wife and I now often only put that up with nothing else on long downwind runs in everything from 150 to 70 deg angles in winds up to 22knots actual. All good for us, but Gordon in hull no. 12 has a para sailor and swears by it. I just though I would confuse you further.

    Tim & Sandy
    S/V 1 Giant Leap ( Helia Hull no. 7)

    1. Thanks for the extra confusion! I’ve been studying the North website quite a bit and the no. 5 looks like an interesting option. How is your light wind performance with the sail?

      We’re getting the factory bowsprit and if we can find the right combo of a Code 0 (or whatever you want to call it!) we can leave on a furler and something like parasailor for more downwind sailing, that’s probably the way we’ll go.

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