It is difficult to draw a line between what most people call a boat and a craft logically entitled to be called a yacht. Actually, any power or sailing craft used exclusively for pleasure is a yacht. On the other hand, most of us think of a yacht in terms of a craft fitted for cruising and requiring more than the usual two-person crew.

For the sake of argument, let us call anything with an over-all length of 30 feet or more a "big boat." Such a craft will hardly be cat rigged and there is some question about her being a knockabout although there are many large boats that are true knockabouts. The chances are that she will be a yawl, a ketch, a cutter, or the latter's sister, a sloop. Where she differs mainly from smaller craft is that she will probably have several special sails for particular purposes.

These may include spinnakers, balloon jibs, and a variety of other light sails that are hoisted when more speed is desired than can be obtained from the normal working canvas. Let us hasten to say that some small boats also have light and special sails. Many of the little one-designs can carry spinnakers. Most of them are also rigged with what is known as Genoa jibs.

To some extent, light sails cannot be too closely defined. For example, a balloon jib may be cut full enough to be used as a spinnaker. Even a Genoa can be set to act as a sort of semispinnaker. The following definitions are thus open to some criticism. A Genoa jib is larger than the fore triangle, which is what the triangular space is called that has the mast as its after limit, the deck as its base, and the forestay as its third side. An ordinary jib - in some cases called a staysail as it is hanked to the forestay - fits within the fore triangle.

The spinnaker is handkerchief light, has a lot of belly, and is often called a bag. Like the ballooner, it is set in stops, but it is used only when the boat is running before the wind. Broadly speaking, it is set across the boat rather than fore and aft. To accomplish that, there must be a spinnaker boom. This is a light spar having a fork, crotch, or special metal fitting at its inboard end to fit the mast.

The outer end of the boom has a snap hook to which the tack or outer lower corner of the spinnaker is made fast. The opposite corner, or clew, is attached to the spinnaker sheet, which is passed around the forestay and carried aft outside the shrouds on the side opposite to that on which the spinnaker boom is to be run out. A guy from the end of the boom is carried aft outside the shrouds on the side where the boom is to be rigged.

In setting, the spinnaker boom is laid on deck parallel to the center line of the boat. The spinnaker is hoisted in stops and the sheet and guy are carried aft. When planning all of the foregoing, you must decide which side of the boat the main boom will be carried on, for the spinnaker boom must be run out on the opposite side.

As the course is directed before the wind, the spinnaker boom is quickly run out, pointed as far forward as possible. A man aft takes up on the guy to bring the boom aft until it is more or less at right angles to the center line of the boat. A sharp pull on the sheet will then break the stops and the sail will fill with tremendous power. If cut very full, and made of very light canvas, it is often called a parachute spinnaker because when filled, it looks so much like its namesake. Once it is drawing, the working jib can be either taken in or, if you are expert, trimmed on the side opposite to the spinnaker boom so that some wind from the spinnaker is spilled into it.

There is of course much more to be learned about sailing a yacht, but this at least gives you a taste. Happy sailing!