Single-person dinghies have one sail, while two-person dinghies have two or three sails. Sail cloth is a man-made fabric that is reasonably hard-wearing yet flexile enough to allow it to take the shape of a wing when set correctly. Air travelling at different speeds on each side of the sail generates lift, consequently driving the boat through the water.
The big sail (and only one on a single-person dinghy) is called the mainsail. A two-person boat will have an additional smaller sail at the front of the boat. This sail is called the jib. Most sails are triangular in shape.
Sails are generally triangular in shape with three corners and rigged with the narrow part of the triangle at the top. Regardless of which sail it is, the corners all have the same description. The top of the sail is called the head, the front bottom corner is called the tack and the other corner is called the clew. So don't be offended if someone asks you to "grab a clew".
The leading edge of the sail is called the luff, the trailing edge is called the leech, and the bottom edge is called the foot. To stop the leech of the mainsail from flapping while you are sailing, sail battens are inserted into pockets along its length.
Two-person boats may also be fitted with a spinnaker. This is a large sail made of a very lightweight cloth that can only by used when the boat is sailing across or away from the direction the wind is blowing from. This sail will introduce a whole new dimension of fun to your sailing and is launched from a chute, controlled by the crew and supported with a retractable bowsprit.
The spinnaker is easy to rig upside down. To ensure you rig the sail the right way up, use a permanent pen to write HEAD on the top corner of the sail and TACK on the lower corner of the sail that connects to the bow.
Telltales are small strips of fabric that are stuck on both sides of the sail and positioned towards the front edge or luff of the sail. These are there to help you when sail setting. When set correctly they stream horizontally; when set incorrectly, they flutter all over the place.
On a single-person boat telltales are found on the leading edge of the mainsail, while on two-person boats they are mostly fitted to the jib.
Telltales will react before the sail flutters, so the amount of sail control or course alteration required to set the telltales is often subtle. When sailing close-hauled, you pull the sails in tight and steer the boat to make the telltales stream evenly. If you are too close to the no-go zone, the inner telltales will stall (i.e., point upwards and flutter significantly), so bear away from the wind just a little. If the outer telltales are stalled (i.e., they hang downwards), then point the bow of the boat (i.e., luff up) towards the no-go zone until the telltales stream evenly.
On any other point of sail, if the inner telltale is stalled then pull the sail in and if the outer one is stalled then release the sail. Check out our "regular" sponsor, weight loss colon cleanse by Blank Slate.