BY ROBB LOVELL
If at first you don’t have speed, trim, trim, and trim again
In “Testing the Waters in PHRF Part 1,” November 2018, Robb Lovell introduced us to the world of PHRF sailboat racing. He encouraged interested sailors to dip their toes in those waters and outlined practical steps for getting started. In this second article in the series, Robb gives tips for optimizing the performance of a good old boat to improve the chances of success on the course. Much of the advice in this article will help non-racers get more out of their boats.
Racing is all about speed, and when racing a sailboat, the principal factor in generating speed is sail trim — setting and shaping the sails to derive power from the wind in the most efficient way.
On a conventional sailboat with a modern rig, the headsail and the mainsail effectively function as a unit. The headsail creates lift and drive for the boat and also directs airflow over the mainsail. When trimmed in concert with each other, the two sails keep the boat balanced and fast.
Sails are airfoils, and are subject to the same aerodynamic lift and drag forces as airplane wings. Obtaining the best performance out of an airfoil depends largely on setting it at the correct angle of attack — the angle at which the wind meets the sail. To identify this angle, sailors use telltales.
Telltales (sometimes called ticklers) are perhaps the most important tool sailors use to ensure their sails are properly trimmed for maximum efficiency and boat speed. Usually short lengths of yarn or narrow tape, they are sewn or glued to a sail near the luff.
On the headsail, telltales are used to indicate the airflow close to the surface of the sail near the luff. A common arrangement is to affix three telltales about a foot to 16 inches aft of the luff and on both sides of the sail, spaced at one-third of the luff length up from the tack, at the center of the luff, and one-third of the luff length down from the head. To use them, the helmsman must be able to see them, and the best place from which to view them is the windward side of the cockpit, which is why many helmsmen steer while sitting on the windward rail.
Telltales spaced along the luff in this way provide feedback on what is occurring on each third of the sail. For example, if the bottom two groups are flowing aft nicely but the top telltales are breaking upward, that shows that the leech is open and is spilling wind off the top third of the sail.
When all the telltales on both the windward and leeward sides of the sail are flying aft smoothly, airflow across both sides of the sail is laminar, the ideal condition, and the sail is set at the correct angle of attack.
On the mainsail, telltales sewn into the leech near each batten pocket will show whether the airflow off the sail is smooth or not.
Some sailors also attach telltales about a foot to 18 inches aft of the luff of the mainsail, spaced vertically as on the headsail. These groupings provide feedback on what is going on at the top, bottom, and middle of the mainsail.
While telltales on the sails show how the wind is interacting with the sails, telltales tied at about head height to the backstay and to the port and starboard upper shrouds indicate the direction from which the wind — the apparent wind — is striking the boat. Perched on the windward rail, the helmsman doesn’t have to look up at the masthead windvane or down at the wind instruments but can see, by glancing at the telltales on the sails and shrouds, both the wind direction and the state of trim.
The backstay telltale is handy for downwind work, especially when the masthead vane is affected by the boat’s rolling motion.
In search of good sail trim
The object of trimming sails is to achieve the smooth airflow across them that will make them perform at their best. The most important factors are the sail’s shape and its angle of attack, and several controls allow these to be adjusted to suit the wind direction and strength.
Halyard –On headsail and mainsail alike, the halyard sets the tension in the luff. When the sail is full and drawing, horizontal wrinkles emanating from the luff indicate too little luff tension for the wind strength; vertical wrinkles along the luff indicate too much luff tension. In either case, the tension can be corrected by adjusting the halyard.
To take the guesswork out of setting the halyard tension when hoisting a sail, mark the halyard with a whipping or indelible marker where it exits its clutch when set for a moderate wind. Use that mark as a starting point when first hoisting the sail, then ease the halyard if the wind on the racecourse is light or increase the tension if the wind is heavier.
Jibsheet lead position –The angle at which the jibsheet pulls on the jib’s clew has a big effect on the sail’s shape and the airflow across it. For this reason, the jibsheet lead is usually mounted on a car that slides on a track so the lead position can be moved forward or aft.
Moving the lead aft puts less down- ward tension on the leech. This opens up the leech aloft — adds “twist” — and depowers the top of the headsail. If the upper jib telltale is lifting while the lower two are flying aft, the sail has twist (see “Twist and the Jib,” above).
Twist can be helpful when sailing in heavy air and the boat is overpowered. Move the jibsheet lead aft and look up at the top inside jib telltale. It will now be flying upward instead of aft, because the top of the sail is open and releasing wind pressure from the top third of the sail.
Easing the sheet, as when bearing away to a reaching course, allows the jib’s clew to rise and the leech to open up. Take out the resulting twist by moving the sheet lead forward.
To establish a baseline for the jibsheet lead position, find the spot on the track where, when sailing close- hauled in moderate wind, the sheet is at about 45 degrees to the deck and all three luff telltales are breaking evenly. Mark this position on the track with a Sharpie. If you have jibs of different sizes, set a baseline for each one.
Mainsail outhaul –The outhaul sets the tension in the foot of the mainsail. Tensioning the outhaul flattens the sail, increasing the angle of attack and reducing power, and provides a way to adapt to a stronger wind. Easing the outhaul deepens the “draft” of the sail (see the diagram on the facing page), giving it more power, which is helpful in lighter wind or when sailing downwind. To be effective in heavy air, an outhaul needs purchase. In the heyday when good old boats were new, many were built for club racing, and some were equipped with a multi-part tackle fitted inside the boom.
Cunningham –Named for its inventor, America’s Cup winner and yacht builder Briggs Cunningham, this is a downhaul on the lower portion of the mainsail’s luff. It is used in heavier air to depower the sail by increasing tension in the luff of the main, which flattens the sail, opens the angle of attack, and pulls the point of maximum draft forward.
There is no Cunningham on a headsail, as it is headstay tension that dictates the sag in the headstay and therefore, to some extent, the sail’s draft (see “Backstay,” below).
Boom vang –The vang acts to tighten the leech of the mainsail by limiting the upward movement of the boom. A tight leech in lighter winds ensures that the upper part of the sail is more effective. Easing the vang will allow the boom to rise, loosening the leech and causing the battens to twist off to leeward and spill wind off the upper part of the sail, depowering it. Tensioning the vang will take out twist.
Mainsheet and traveler –Used in concert, the mainsheet and traveler control the position of the boom and the angle of attack of the wind on the mainsail. The traveler controls the bottom of the sail, especially when sailing upwind and close reaching, while the mainsheet controls the tension on the leech, and therefore twist. When the traveler is all the way to leeward, the mainsheet and boom vang control the amount of tension on the leech.
The primary use of the traveler is to keep the boom centered when sailing close-hauled. Even when the mainsheet is tightened in fully, the boom will still fall off to leeward. Moving the traveler to windward will center the boom and ensure the mainsail is most effective. In heavy air or in gusts, running the traveler down to leeward will spill the wind off the mainsail, depowering it.
Backstay –Many good old boats are equipped with a means to adjust the backstay tension. On a masthead rig (where the headstay is attached at the very top of the mast), the backstay’s main function is to add headstay tension, which flattens the entry of the headsail and can improve the boat’s upwind pointing ability, especially in moderate to heavy air.
On a fractional rig, the backstay serves to bend the top of the mast aft. This shortens the distance between the top of the mast and the end of the boom, opening the leech of the mainsail and adding twist, which depowers the mainsail, especially toward the head. This can be helpful when a boat feels overpowered. Conversely, releasing backstay tension powers up the top of the mainsail. The running backstays can be used to control the tension in the headstay.
In high winds, maintain a tight headstay and lots of backstay tension (or running-back tension on a fractional rig) to keep the headsail flat. In lighter winds, reduce the headstay tension for a deeper, more powerful sail.
The backstay is not effective at depowering the mainsail on a masthead rig. That is accomplished principally with the mainsheet, the traveler, and the boom vang.
All the sail adjustments described above are made with control lines, and how those control lines are led and identified will have a big effect on how efficiently the crew can work to achieve the desired sail trim. A well-thought-out deck layout will pay dividends, and some sailors say there is an art to it. While personal preference plays a part in laying out a deck, some proven best practices are widely adopted by racers.
Refining a deck layout so that it works best on a particular boat takes some trial and error over the course of many races and many practice sails. To get some ideas to start with, walk the docks and note how other boats are set up, and engage in discussions with other sailors.
Here are some tips for laying out control lines:
Arrange control lines so they are easy for crew to access without obstructing other crewmembers doing their jobs.
Think through sail changes. Picture the steps, who does what, and where the crewmembers are positioned on the boat. Set up the control lines to reflect this.
Ensure every control is set up with enough purchase (mechanical advantage) that the weakest crewmember can easily operate it.
Label all the controls so they are easy to identify. Label clutches and cam cleats with the names of the lines they control. It’s also helpful to use lines of various colors. “Hey, Jenny, can you ease the vang a little? It’s that red line over there,” is much better than pointing at a group of identically colored lines and letting Jenny guess which one you are referring to.
On the racecourse
An older gentleman who was an excellent racing sailor told me something that I always keep in mind while racing. “If the boat is fast, leave it alone, but if you are behind or feel slow, be constantly dissatisfied.” That is, keep adjusting and trimming until it feels right; don’t be content until the boat feels, and is, fast.
A common sailing expression worth remembering is “If in doubt, let it out.” Whether trimming the main or the jib, it’s easy to tell from looking at the luff if it’s undertrimmed and out too far — the windward telltales will droop and the luff will flutter. It’s much more difficult to identify an overtrimmed sail because it looks full of pressure. So, if the sails look full but the boat feels slow, ease the sheets while paying attention to the knotmeter (or GPS), and watch the luff telltales, which should come alive and start streaming aft once the sail is properly trimmed.
When sailing in heavy air, the sails should be trimmed flat (think “Flat is fast”). To achieve flat, tighten the sail controls — halyards, mainsail outhaul, and Cunningham.
Conversely, in lighter air, the sails need the power gained by easing the controls to give them deeper draft (think “Full is powerful”).
When beating to windward or close reaching, pay attention to how much the boat is heeling. Sailors new to racing sometimes make the mistake of thinking that sailing heeled over at 25 degrees is fast. It might feel fast, but most boats sail faster when sailed on their feet. Too much heel usually means the boat is over-canvased. It will sail faster, and with less pressure on the helm, with the sails depowered or reefed. Keep in mind that pressure on the tiller or wheel translates to drag on the rudder, and drag is the enemy of speed and performance. Adjust the sails to balance the boat and it will come alive with speed.
A clinometer shows the boat’s angle of heel. Installed where it’s visible from the helm, it will provide one more piece of information helpful to new sailors and racers alike.
If the boat feels overpowered, start depowering it by opening the leeches of both sails. Move the jibsheet leads aft and ease the vang and/or the mainsheet. The twist this adds will depower the sails by spilling wind off their tops.
Still overpowered? It‘s time to start shortening sail by reefing, or by changing to a smaller headsail. On many boats, the first step is to reef the mainsail, as shaking a reef out of the main when turning downwind or if the wind dies is easier than changing back to a bigger jib.
Beyond the sails
Boat speed is not solely a function of sail trim. The hull and its appendages — keel, rudder, and propeller — are big factors, as they all create drag.
It stands to reason that the smoother and more fair the boat’s bottom, the less drag it will create, and reducing drag can dramatically improve a boat’s performance. The obvious remedy is to keep the bottom clean, but if the racing bug bites deep, there are steps the serious sailor can take.
Many a good old boat has a fin keel and a spade rudder, both of which are designed as airfoils. To work efficiently, they need to be fair, smooth, and symmetrical. Some time spent in the boatyard with fairing compound and templates of the keel and rudder will pay back.
On a boat with an inboard auxiliary, a fixed-blade propeller can cause a lot of drag and significantly reduce performance under sail. On many boats, swapping it out for a folding or feathering prop can increase boat speed by more than half a knot. While some folding props may not drive a boat as efficiently as a fixed-blade prop, some feathering models perform almost as well, even in reverse. The loss of power is a small trade-off for the increased performance under sail — and after all, it is a sailboat!
The best way to learn how to sail a boat fast is to get out there and sail or, better still, go out and start racing. Experiment with sail trim to see how it affects boat speed, and adjust the deck layout if that will improve crew efficiency. The wind, sea conditions, currents, competitors, and the racecourse all will be in flux and change, but a well-set-up vessel will be a constant in a sport that has few constants, and will provide a stable foundation on which to build performance.
When helming, I don’t simply look at where I am going but scan everything around me, shifting my focus between different features on the boat and outside the boat. I look at my sails to check the telltales and trim, then scan the racecourse for competitors and to spot the next mark of the course. I then move my focus to my instruments to check my depth, speed, and course. Scanning like this, focusing on the important things inside and outside of the boat, lets me take in all the relevant information I need to sail my race.
Sailing upwind on Jade, we start to trim the main using just the traveler. We tighten the mainsheet to put the ideal amount of tension on the leech of the sail and use the traveler to change the sail’s angle of attack.
One of the best additions I made to Jade’s deck layout was to mount a simple $20 cam cleat on the mast for the spinnaker halyard. As well as preventing the halyard from pulling off the arms of the crewmember jumping it in heavy air, it freed up the cockpit crew from having to tail the halyard so they could work the guy and pole controls on launching the spinnaker. Marks on the spinnaker halyard at this cam cleat and at the clutch let the crew know when the spinnaker is fully hoisted, which other- wise can be difficult to see when jumping it during a race. My foredeck crew told me that this was the greatest improvement I had ever made on the boat.
Robb Lovell grew up sailing on Lake Huron aboard his family’s Endeavor 40, where he caught the sailing bug. That was about 20 boats ago. Rob enjoys buying and restoring boats, and is an avid racer and cruiser based out of LaSalle Mariner’s Yacht Club (LMYC) in Ontario. He currently races on a Cal 9.2 named Jade, but owns three other sailboats and a tugboat. Yes, he has a problem!