Yacht Racing Association.

Instructions for the measurers issued by direction of the Council.

The following from Lloyd's Yacht Register of 1897.

The Measurer shall not measure for the Yacht Racing Association a yacht or boat which he has designed or built, or which any firm he is interested in has designed or built ; nor shall he measure any yacht in which he is interested as owner or otherwise.

Before measurement the yacht must have on her length and girth marks, and before testing the marks and measurements, the Measurer must ascertain from the owner or his.representative that the yacht is in her correct racing trim.

All sails, spars, gear, &c., as usually carried by the yacht when racing, must be on board, and also the usual racing crew when the measurements for the length, or girth, are being taken or checked.

The Measurer may allow sails, spinnaker gear, tackles, &¢., to be put amidships whilst the measurements and marks for the length and the girth are being tested.

The measurements to be taken are the length, breadth and girth, and the lengths of the spars, or dimensions of sails, in accordance with the Yacht Racing Association rule No. 3, for the rating of yachts, as follows:

The rating of every yacht entered to sail in a race, shall be ascertained by adding together length (L), beam (B), 0.75 of girth (G), and 0.5 of the square root of the sail area (SA), and dividing the sum by 2 according to the following formula :—

In all ratings, figures in the second place of decimals below 0.05 shall be disregarded, and those of 0.05 and upwards shall count as 0.1.

The length shall be taken between the outer edges of the Official marks of the Y.R.A., as placed by the owner at the bow and stern of the yacht this length to represent the extreme length for immersion, provided always that if any part of the stem or stern- post or other part of the vessel below the marks for length project beyond the length taken as mentioned, such projection or projections shall, for the purposes of the rule, be added to the length taken as stated; and pieces of any form cut out of the stem, stern-post, or fair-line of the ridge of the counter, with the intention of shortening the length, shall not be allowed for in measurement of length, if at or immediately below the marks for the length, nor above if within 6 inches of the water level.

The breadth shall be taken from outside to outside of the planking, in the broadest part of the yacht, and no allowance shall be made for wales, doubling planks, or mouldings of any kind.

The girth shall be taken from L.W.L. to L.W.L. under the keel ata station 0°6 of the distance between the outer edges of the length marks from the fore-end. The girth shall be measured along the actual outline of the vertical cross section at that station at right angles to the L.W.L., see Figs.1 and 2, aá, and Figs.3 and 4. If the draught forward of that station, ee, Fig. 2. (not including the girth of a bulb, if any) exceeds the draught at that station, aá, twice such excess to be added to G. In taking these measurements all hollows in the fore and aft under-water profile of the vessel to be treated as filled up straight. Should a piece be added, as at b, then a line must be drawn from b to c, and the girth be measured to d. (Fig. 1.)

In the case of a centre-board, twice the extreme drop of the board below the keel to be added to the girth as taken at aá; and if the board is dropped below the keel at ee, the excess at ee shall, nevertheless, be added to girth in accordance with the rule. In all cases centre boards or plates, bulb or ballasted, or otherwise, to be measured as fixed keels.

Owners shall mark the length for rating of their yachts on both sides, at the bow and stern, in such a manner as the Council may direct, with the official marks supplied by the Y.R.A., which marks shall at all times represent the extreme length for immersion when the yacht is lying in smooth water in her usual racing trim, including racing crew on board at and about the mid overall length.

Owners shall mark the points for measuring the gith as follows: by fixing three metal discs of suitable size on each side of the yacht, not less than 2 ins. or more than 6 ins. above the load water-line level, and parallel thereto, and not less than 3ft. or more than 6ft. from end to end, and so that the centre mark, a, of the three, coincides with the distance 0.6 from the fore edges of the bow marks (see Figs. 1 and 2, a); and the owner shall also place a dise coinciding with this centre mark (perpendicular to the load water-line level), under the rail or covering board and another on the side of the keel perpendicular to the load water-line level, see a, Figs. 1 and 2. The distances between the load water-line level and the horizontal marks to be measured when the yacht is afloat in smooth water with crew on board according to the rule, and deducted from the girth as obtained from centre mark to centre mark.

Length.

The length (L) for use in the formula shall be obtained by measuring the length over-all on deck, and deducting from this length the distances in to the bow and stern marks as fixed by the owner, from perpendiculars let fall from the bow and taffrail, as shown in the diagrams. These perpendiculars if measured when the yacht is afloat, are to be obtained by a hand lead sunk two or three fathoms deep, so as to ensure a steady line to measure from. The distances in from the line are to be taken by a rod placed parallel to the water surface, as shown in the diagrams.

After the over-a]l length has been taken the Measurer must see that the crew are placed at and about the mid over-all length. (See the extract from Rule 14 overleaf -- n.b. not included). He must then ascertain that the yacht is not immersed at the load water-line beyond the length represented by the owner’s marks at the bow and stern.

If a yacht is measured in a tide way, the Measurer must view and verify the marks in smooth and during slack water; and the overhangs must be measured in smooth and during slack water.

If the measurement for length is obtained when the yacht is ashore the position of the bow and stern marks must be afterwards verified or checked when the yacht is afloat in racing trim, in smooth water, and before the certificate of the measurements is sent to the Secretary.

The over-all measurement must be taken parallel to the L.W.L. above the deck, starting from any convenient point forward on the rail, knee, &¢c., ahead of the fore end of the load water-line.

When the length over-all is taken with rods, a line should be stretched taut from the point forward to the taffrail to facilitate the accurate shifting of the rods.

Beam.

The beam may be measured when the yacht is afloat or ashore. The beam shall be taken by means of a straight edge and plumb line.

Girth.

The girth is to be taken from centre disc to centre disc (a á) at right angles to the load water-line under the keel, following the curve of the cross section as shown in Figs. 1, 2, 3 and 4, and must necessarily be measured when the yacht is on the stocks or laid ashore. When the marks are tested afloat the heights between such marks and the covering board must be compared with the measurements taken on shore.

When the yacht is afloat for the other measurements, the Measurer shall check the level of owner’s girth marks with regard to the water-line level.

The distance between the water level and the metal discs marking the horizontal line, ~ or line parallel to the line of flotation, must be accurately measured when the yacht is afloat in smooth water, in racing trim and crew on board stationed amidship in accordance with the rule, and deducted from the girth as taken from centre mark to centre mark.

In the case of a yacht being fitted with a centre board or lifting keel, the owner shall either block up the yacht so as to show the board or lifting keel lowered to its full extent, or shall furnish the Measurer with a true drawing to scale of such centre board or lifting keel lowered to its full extent.

Spars and sails.

In measuring the main boom length from the mast to the pin of out-haul shackle, the Measurer should see that the traveller, whether on a slide or round the boom, is chock out. For this purpose the clew of mainsail should be unshackled and the traveller hauled out to the farthest point to which it can be taken.

The Measurer should ascertain for himself the point on the bowsprit or cranse iron to which the base measurement for fore triangle must be taken.

In measuring the height for fore triangle, a piece of white linen should be attached to the ring of the tape, and the tape can be then hoisted by the signal halyards.

Before measuring a jackyard, the sail should be bent to it, or the foot laid parallel to the yard and fairly stretched; and, as a check, besides measuring the distance from the sheet to the outer lacing hole, the number of cloths from sheet to clew should be counted.

All measurements should be taken and recorded in the Measurement Book twice,and a third time if there is any material disagreement.

A steel tape or rods must in all cases be used for taking the measurements.