Using Telltales to Trim Headsails Correctly

By

Roger St John

Owner of P-19 #1100 "Little Zephyr"

In a message pertaining to sailing a Potter to windward Roger wrote:

I think you need to do 2 things:

1) Get the sails trimmed correctly

2) Get the boat pointed the right direction.

Installing a set of telltales on your headsail will help you do these 2 things.

First, here's how to install telltales:

Get a piece of yarn or ribbon. You will want one piece of this on each side of your headsail. It should be attached about 8 inches back from the front edge of the sail, about halfway up the sail.

If you use ribbon, then you can tape a piece to each side of the sail. If you use yarn, you can either tape it on or use a needle to stick it through the sail, tying a knot on each side of the sail so the yarn won't pull out. You want each telltale to be about 6 inches long.

If you will be sailing with the sail partially furled, then add additional telltales to the sail so they will show when you have the sail partially rolled up. You will want these positioned so they end up about halfway up the sail when it is rolled. Also, you will probably want them about 1-foot back from the front of the sail. This is a little further than suggested above because of the extra turbulence from the rolled-up portion of the sail.

Now, to use these telltales:

I actually disagree with the advice to "let it out" (main sail) when you are trying to sail to windward. Here are my suggestions.

Set the boat on one tack. First, pull the mainsheet in until it is fairly tight. The end of the boom should be well inside the edge of the boat. Really, unless you are putting some muscle into it, you don't need to worry about having the main in to tight. Sometimes, it is beneficial to have the main a little looser, but having it tight isn't going to prevent you from sailing well to windward.

Next, pull the jib sheet tight. If you are sailing in 6-7 knot winds, then you should probably be pulling the jib sheet in until there is significant but not heavy resistance -- maybe 10 pounds of pull. The if you have the genoa, then the sail should come in reasonable close to the outer shroud, maybe 6 inches away or less.

With the sails adjusted like this, look at the telltales on the headsail. You will need to look at both the one on your side of the sail, and look at the shadow of the one on the far side of the sail. You want to have both of them flying back like little flags.

If the one on the close side of the sail is flipping all around, then you are too close to the wind (and probably about to come to a halt). If the one on the far side of the sail is flipping wildly, then you are too far off the wind -- steer up slowly until it flies back nicely.

I recommend (if possible) that you do the above steps where you can stay on one tack for a long time. After you get the telltales on both sides of the sail to fly back properly, then do some experimenting. Turn up into the wind just a little and see what happens. Turn off the wind and see what it does. After you get a feel for how the telltales behave, then try trimming the sails.

Adjust the sails (one at a time) in or out just an inch. Maneuver the boat until the telltales fly correctly again, and see if the new sail position gets you closer to the wind without loosing too much speed.

Once you get used to sailing the correct course on one tack, then practice tacking back-and forth. After you learn where you want the boat to point on the new tack, it will be easier to get the boat going again on the new tack.

PS - Right after you change tacks, it may help to steer a little further off the wind (10 degrees or so) and leave the jib sheet just a little looser until the boat gets back up to speed. Once you get the boat moving good, then tighten things back up.

Finally, a few other comments:

Someone else mentioned it, but your daggerboard MUST be down to sail to windward. Also, if the winds are truly 6-7 knots, this is rather light. If you have the genoa, you will need most of it out to sail to windward in these conditions. If you have the lapper, you will need it all out to sail to windward.