Some dinghies and yachts have wind vanes to provide information on where the breeze is coming from… which can be especially useful when running downwind so you know when you are running by the lee (ie. when you are sailing, the boom is normally on the other side of the boat from where the wind is coming from. When sailing by the lee, you are sailing with the wind, but the wind has moved around and is just coming from the same side as the boom is on, which can cause you to jibe unexpectedly).
They are attached to the mast, generally located between the deck and boom, or at the top of the mast.
Most of us want to get the maximum speed out of our boat when sailing, regardless of whether we are Laser sailing, sailing on any other type of dinghy, or a yacht. And this means that we have to be able to trim the sail efficiently to get the most out of it. By having tell-tales on the sail, it gives us a good indication of how we have to trim the sail to be optimal.
Tell-tales are small strips (approx 10cm or 4in long and 5mm or 1/5in wide) of tape or material located on both sides of the sail. Sometimes there may be a few sets of tell-tales on the 1 sail. Light yarn tell-tales are preferred by many for their
If the tell-tale on the windward side is flapping or hanging straight down, the air is not flowing over that surface of the sail optimally, so you need to pull it on (you may also see an uneven surface in the front of the sail along the mast edge, or the luff).
Conversely, if the leeward tell-tale is flapping, the sail is pulled on too much and needs to be eased to get the air flowing nicely over that part of the sail.
The art is to get the tell-tales on both sides of the sail flowing nicely. This means that the air is flowing over both surfaces of the sail optimally, and it is trimmed correctly.