Testing Your Sail Trim Knowledge - SailNet Community
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Testing Your Sail Trim Knowledge

Good performance is the result when sails are trimmed in the manner their designers intended.
Most sailors would be astonished if they knew just how scientific sail design and engineering has become, and most would be equally amazed to find out how little the average cruising sailor knows about sail trim. A little knowledge and understanding can go a long way towards faster and safer sailing, and more importantly, your sails will last longer if they are trimmed as designed instead of left to flap in the wind.

In order to make this discourse on sail trim fundamentals more fun to digest, I've arranged it as a true-or-false quiz. So go ahead and take this test to measure your knowledge. Just keep track of your score as you go along and you'll see where you stand at the end (see Sidebar).

Q: When you are sailing hard on the wind, you should generally have equal tension on the leech and foot of your headsail, true or false?
A: As a general rule the leech and foot will have equal tension. If the foot is too loose, move the sheet lead aft. Similarly, if the foot is too tight move the lead forward. Following the line of your trim stripe will give you a good average setting for the genoa lead. The answer is True.

When your crew gets a little too intimate with the genoa, it enhances sail shape, true or false?

Q: As you ease down onto a reach, you should move the genoa lead aft, true or false?
A: As you bear away onto a reach you need to move the lead position forward. This will keep tension on the leech and retain power in the sail. Keep the lead positioned so that the front of the sail breaks evenly when you luff. The answer is False.

Q: When you see horizontal wrinkles along the luff of your genoa you need to ease the halyard, true or false?
A: You need to tighten the halyard to remove the wrinkles. Create sufficient tension on the luff of the sails so that there are no wrinkles, but do not over tighten. The answer is False.

Q: As the wind increases, the fabric stretches and your headstay sags a little. As a consequence the draft in your headsail moves aft. To compensate and to keep the draft in the right place you need to tension your halyard, true or false?
A: By tightening the halyard it stretches the fabric along the luff of the sail and drags the draft forward. It is not critical for the cruising sailor to constantly be adjusting halyard tension, but being aware that the halyard will stretch and the efficiency of the sail will be lost as the wind increases will allow you to set the sail up properly in the beginning. The answer is True.

Setting a staysail on a inner forestay is a good option for reaching, true or false?
Q: You can set a staysail on your inner-forestay when reaching, true or false?
A: A "double-headsail" rig is a very efficient way of sailing on a reach. The staysail splits the gap between the headstay and the mast creating two "slots." It is the wind flowing through the slots that provide drive. The staysail not only creates a second "slot," it also forces the wind to increase in strength as it blows between the sails because the gaps are narrower. Be aware that as the wind comes forward until you are sailing upwind, the staysail loses it efficiency until it can actually hurt your performance. The Answer is True.

Q: It is the back end of the mainsail that provides lift, true or false?
A: As a general rule, your headsail provides drive and the back end of the mainsail working in conjunction with your keel provides lift. The answer is True.

Q: The harder you sheet your mainsail, the faster you will go, true or false?
A: It's important that you trim your mainsail enough so that it works to provide lift, but equally important to not over trim the sail. The adage, "when in doubt, ease out" is a good one, but remember that if the sail is too eased you will not be able to point and you will end up making a lot of leeway. The answer is False.

What's the rule of thumb for leech tension on the mainsail?
It's important to keep tension on the leech of the mainsail when you are reaching, true or false?
A: As you bear off onto a reach, it's probably better to ease the sail out using the main traveler if you have one, rather than simply easing the mainsail. This keeps tension on the back end of the sail providing power. A boom-vang will achieve the same result. Once you are overpowered you can ease the tension on the leech to depower the sail. The answer is True.

Q: If you need extra power in your mainsail, especially in light winds, you should ease the foot by easing the outhaul, true or false?
A: By easing the outhaul you induce more shape into the lower part of the sail, which in turn provides overall power to the sail and increases performance. The answer is True.

Q: The same logic that applies to keeping the draft in the right place of your mainsail applies also to your headsail, true or false?
A: As already pointed out, once the wind increases, the maximum camber in the sail will drift aft. Tensioning the main halyard will drag the draft forward keeping it at around 50 percent where the sail is most efficient. The answer is True.

"If your sail keeps collapsing, you need to ease the pole forward and sail a lower course."
Q: You are sailing downwind with your headsail poled out, and the sail keeps collapsing. You need to bring the pole aft and sail a higher course, true or false?
A: Poled-out headsails do not collapse in the lee of the mainsail like spinnakers. If your sail keeps collapsing, you need to ease the pole forward and sail a lower course keeping the wind perpendicular to an imaginary line between the luff of the sail, and the clew. The answer is False.

Q: You cannot roll up or reef your poled-out genoa when a squall comes up without letting it luff, true or false?
A: Most manufacturers or roller-furling gear warn against rolling up a sail under load, but in practice it is often necessary to do so. A dedicated winch for the control line in the cockpit is a useful piece of gear. When you go to reef, let the pole forward to depower the sail, and then start winching the sail in. The answer is False.

Q: A pole-guy, in addition to the foreguy, can be useful for setting and dousing poled-out headsails and spinnakers, true or false?
A: If you are sailing shorthanded, it's good to be able to set the pole in place with two guys and a topping lift, and have it ready before unrolling or hoisting the headsail, or setting your spinnaker. With two guys set you only have to worry about one thing at a time. A pole-guy attaches to the outboard end of the spinnaker pole and runs back to the deck. The answer is True.

Q: When jibing a poled-out genoa, you should first lower the pole end and then haul the clew across to the new windward side as you jibe, true or false?
A: The easiest way to jibe a poled-out genoa is to roll it up first, switch the pole and sheet, and then roll the sail out again after the mainsail has been jibed. The answer is False.

Q: It is a good idea to put reference marks on sheets, guys, downhauls and topping lifts, true or false?
A: By having marks on your control lines you can preset everything before setting your spinnaker or headsail, and you will not find yourself suddenly overpowered with a sheet too tight. The answer is True.

Trimmer or Talker?

Do you just talk the talk or can you actually trim the sails on your boat to their best advantage. Each of the above questions is worth five points. Add up the number of total questions you answered correctly and multiply by five; then refer to the chart below to see how you scored.

60-75 pointsyou're ready to circumnavigate

45-60 pointstrade winds here we come

30-45 pointsbetter stick close to shore

less than 30 pointstime to brush up; let's take a class


Brian Hancock is offline  
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