In giving a vessel a light boom, however, it should never be lost sight of that about the worst thing in a vessel's outfit is a weak boom. With a weak boom the mainsail can never be made to stand properly if there be the least semblance of a breeze ; and, moreover, so far as danger to the crew goes, a worse accident cannot happen to the spars than the breaking of the main boom.
With regard to the placing of the masts, a great many rules have been given ; but the soundest advice is to keep them as near to the centre of gravity of the vessel as possible, if it is sought to make a yacht easy in a sea-way. The weight of the masts, by lengthening out the radius of gyra tion, much increases the violence of pitching; and the shorter the masts are, and the nearer they are stepped to the centre of gravity of the vessel, the less they will operate to aggravate pitching. A quarter of a century ago, the America introduced the fashion of raking masts aft, and no doubt there was some reason in it, if it were absolutely necessary that masts should be stepped very far forward. By raking the masts aft, their weight was carried aft in proportion to the sine of the angle of rake, and so, although a mast might have been stepped very far into the bows of a vessel, yet would its weight fall very near the centre of gravity. However, experience soon undid this fashion, as it was ascertained that sails of better figures, which could be more easily worked, were to be obtained by step ping the masts a trifle further aft, and upright.
So far as cutters are concerned, the general rule appears to be to step the mast 0.4 of the length on the load water-line abaft the fore side of the stem.* This position is found to be near enough to the centre of gravity of a vessel to avoid any bad effect on her ease in a seaway; and generally, if any good results through stepping a mast Gin. further forward or aft, the good is traceable to the altered position of the centre of effort of the sails rather than to the shift that has been made to the weight of the mast. Of course, if the centre of effort of the sails cannot be altered or adjusted, without shifting the mast, this extreme measure must be adopted ; but the constant craze some sailing masters have for shifting masts backwards and forwards should never be gratified from the more assertion of " I'm sure this 'ere vessel would do a great deal better if her mast was moved six inches further aft ; we shifted the Old Nailsick's six inches aft, and she went as well again afterwards."
This is usually the skipper's " theory," and, as the builder is very properly anxious to do anything to improve his construction, the mast is generally shifted after the skipper's sententious opinion. A mast may require shifting : but often a little addition to the fore foot, or a little taking away from it, or a trifling alteration to the sail plan, will correct a vessel's indif ferent performance and handiness when sailing on a wind.
The mast of a yawl is generally placed a little farther forward, or about •38 of the length on the load line abaft the fore side of the stem. The mast is placed so far forward in order that the mainsail may be large, as the Y.R.A. have limited the extension of the boom aft the stern end of the load water line to two-fifths the beam. The wizen mast of a yawl generally has a slight rake aft, in order that the main boom may clear it, as frequently the length of counter will not admit of it being stepped suffi ciently far aft to clear the boom if no rake be given.
With regard to schooners, the present plan, in order to secure good weatherly qualities, is to make them as much like cutters as possible. In racing schooners at least the comfort of a good large boom foresail is an unknown thing; but the advantage of having a big mainsail, or as much canvas as possible in one piece, is too great to be sacrificed for comfort. In a like way the exigencies of yacht racing have gradually turned the once comfortable yawl, with her wizen stepped close to her rudder-head, into a vessel that, so far as her ease in a sea is dependent on her spars, might almost as well be a cutter.
The masts of a ketch are thus placed ; mainmast 0.11 of the length of load water line forward of the centre of length of load water line ; mizen mast 0.4 abaft the centre of length.