Loose Foot vs. Attached—What's Best?
by Dan Dickison
Racing sailors in particular are keenly aware that once the breeze pipes up, you need to make certain adjustments to keep your sail shape optimized. With a mainsail, that begins with tweaking the halyard to achieve a luff tension thatís in the ballpark for the given conditions. Then—if your boat has a standard Marconi rig—youíll begin making adjustments to the backstay, outhaul, and cunningham to fine-tune the sailís overall shape. Of course, the most frequent adjustments are made using the traveler and the mainsheet, and on board the most aggressively raced sailboats, the latter is rarely cleated.
Of all these controls, perhaps the one most overlooked by non-racing sailors is the outhaul. Most boat owners follow the Ďset it and forget ití approach with this control line. But a properly attended outhaul can afford you surprising control over the lower portion of most mainsails. I say most mainsails because there are different design approaches to the foot section of these sails. On the vast majority of mainsails, you either have a foot thatís attached to the boom via slides or a bolt rope, or you have what is known as a loose-footed arrangement wherein just the tack and some portion of the clew are attached.
It used to be that 90 percent of mainsails seen on board recreational sailboats were constructed with an attached foot. However, that situation started to change during the 1980s after Americaís Cup sail designers began experimenting with loose-footed mainsails. As with most sail design innovations, permutations of this approach eventually trickled down to the recreational arena and became commonplace. These days, the majority of new mainsails are designed with a loose-footed arrangement.
But, besides attachment methods, what really are the differences between a loose-footed mainsail and one thatís attached along the boom? Proponents of the former will tell you that loose-footed mainsails are easier to rig and de-rig because there are fewer attachment points and less hardware involved. Consequently, thereís almost always less friction as well, which is a boon to those trimming the outhaul. Equally important is the fact that a loose-footed mainsail enables you to more easily rig reefing lines by tying the bitter end around the boom. And some sailors will tell you that having a loose-footed mainsail makes it imminently easier tie on a boom preventer, but I recommend you affix preventer lines to the boom by using dedicated hardware like a padeye. (Most booms arenít designed to sustain the point loading that is likely to occur when you tie a piece of line around the sparís midsection and subject it to high loads.) A further advantage to loose footed mainsails is that they make it possible to load full battens into the sail when itís not already bent on the boom, and that is often easier and more convenient.
Are there disadvantages to loose-footed mainsails? Yes, but these are relatively minor. First, while sailing close-hauled with the mainsail trimmed in hard and the outhaul taut, some loose-footed mainsails will produce foot flutter. On board most boats, this is really more of an annoyance than a performance detractor. And second, some long-range cruising sailors customarily use the foot of their mainsail to collect rainwater. Depending upon the amount of rainfall, this can be a pretty efficient collector, and you obviously canít do that with a loose-footed mainsail.
What about mainsails with an attached foot? What advantages does this system offer? The only true advantage to this system is that it allows the mainsail to have a conventional shelf-foot built into it. A shelf foot is characteristically a lighter weight piece of cloth that is sewn along the foot of the sail from the tack to the clew. This section also connects to the mainsail along the boom, ordinarily via slides or a bolt rope. When the outhaul is loosened, the shelf opens up to produce a fuller shape in that portion of the sail. When the outhaul is tightened, the shelf essentially closes up and flattens alongside the boom. The downside is that the hardware involved (slides or bolt rope) will eventually increase the cost of maintaining the sail due to the wear and tear of these items.
It should be clear at this stage why the majority of sail designers these days favor loose-footed mainsails. Neither concept offers a significant performance advantage under sail for most types of boats, but the loose-footed approach can provide significant advantages from a maintenance and equipment handling standpoint. Also, the fact that almost any existing boom can accommodate a loose-footed arrangement, but an attached foot mainsail requires a boom with either a foot groove or a track further strengthens the loose-footed argument. Of course every sailboat has its idiosyncrasies—as do most owners—so discuss these options with your sailmaker before you commit one way or the other. If you do that first, youíll be much happier no matter what option you choose.
About the Author: Dan Dickison is known throughout the sailing community for his in-depth articles on a variety of sailing topics. His resume includes stints as a staff editor at Sailing World, Editorial Director of SailNet, and Editor of Practical Sailor. In those capacities he has written principally about racing, sail handling, and maintenance. He has also written over 50 freelance articles that have appeared in major sailing publications around the world.