Category: 1903 : CHALLENGE N°12


Official Figures Give Challenger 1 Minute, 45 Seconds.

August 19, 1903 - Reliance and Shamrock III., the two great yachts which will race to-morrow for the America's Cup and the world's yachting championship, ...

... of which the cup is emblematic, were officially measured at Erie Basin yesterday afternoon by Charles D. Mower, the measurer of the New York Yacht Club.

1903MeasuresThe sail area of a yacht taken for the purpose of determining her racing length is much less than her actual sail spread. In the accompanying diagram the triangle formed by the broken line circumscribes the measured sail area. The diagram shows at a glance the relative proportions of measured and unmeasured sail spread. Yet it does not show the entire sail spread, for it does not include the spinnaker. While this sail is set only when the yacht is running before the wind, it is a very large piece of canvas. The largest spinnaker of the Reliance measures about 190 feet on the luff, or outer edge; 170 feet on the leech, or inner edge, and 85 feet on the foot.

Water Line 89,66 89,81
Base Line 210,76 187,54
Base of Forward Triangle 84,29 81,40
Spinnaker Boom 83,75 81,40
Gaff 71,90 65,77
Topmast 72,00 69,15
Perpendicular 149,60 144,83
Square Root of Sail Area 127,16 119,74
Sailing Length 108,41 104,27
Sail Area 16169,33 14337,45

The official measurements of the Reliance give her a measured sail area of 16,160.93 square feet. This is equivalent to a square 127.10 feet on each side. Placed in front of the General Post Office it would completely hide that building from the view of the crowds on lower Broadway. The racing length of the yacht is arrived at by adding her waterline length to the square root of the measured sail area and dividing the sum by two. Thus the waterline length of the Reliance being 89.66 and the square root of her sail area 127.16 give the sum of 216.82 which, divided by two, makes her racing length 108.41.


1885 Puritan 7,982.00 Genesta 7,150.00
1886 Mayflower 8,134.00 Galatea 7,505.00
1887 Volunteer 9,260.00 Thistle 8,968.00
1893 Vigilant 11,272.00 Valkyrie II 10,042.00
1895 Defender 12,602.30 Valkyrie III 13,027.00
1899 Columbia 13,135.00 Shamrock 13,491.82
1901 Columbia 13,211.00 Shamrock II 14,027.00
1903 Reliance 16,169.33 Shamrock III 14,337.45

In this connection it is interesting to note that the sail spread of the cup defenders has more than doubled in the eighteen years since the advent of the Puritan.
The sail spread of the Puritan was regarded as enormous at the time, and comparisons of her spars with those of merchant ships was made to the detriment of the latter. Yet her measured sail area was only 7,982 square feet. against 7,150 square feet for the Genesta.
The Mayflower came out in the following year with a measured sail area of 8.134 square feet to sail against the Galatea with only 7,505 square feet.
The Volunteer, in 1887, showed a still further increase with 9,260 square feet, but the Thistle took an even greater jump over previous challengers with 8,968 square feet.
In 1893 the Vigilant dwarfed previous defenders with 11,272 square feet, while Valkyrie II had 10,042 square feet.
The Defender, in 1895, surpassed the Vigilant by nearly 1.400 square feet, her sail area being 12,602.30 and, for the first time in the history of the matches, the challenger exceeded the defender in sail spread. The sail area of Valkyrie III was 13,027 square feet.1903GraphAreaSail75
Then came the Columbia in 1899, with 13.135 square feet, but not up to the mark of Shamrock which had 13,491.82 square feet. Yet the Shamrock was so much shorter than the Columbia on the waterline that the latter had to give her time allowance.
The sail area of the Columbia was slightly increased in 1901, while Shamrock II broke all records. The figures were: Columbia, 13,211 square feet; Shamrock II, 14,027.

This great and progressive increase of sail spread has been rendered possible by lowering the centre of gravityAllowance2 and extending the overhang of the yacht fore and aft. The Puritan's overhang was all aft, and she was only 12% feet longer over-all than on the waterline. The overhang of the Mayflower was also confined to her stern, but she was 15 feet longer over-all than on the waterline. The Volunteer was the first defender to have an overhang forward as well as aft. She was 22.35 feet longer over all than on the waterline. Her draught was only 10 feet, the same as that of the Mayflower, and slightly greater than that of the Puritan. The Vigilant marked a decided advance both in overhang and draught. She was 37.81 feet longer over-all than on the waterline. Her draught was 13.05. The Defender was only 33.55 feet longer over-all than on the waterline, but as she was the first fin-keel defender she showed a great increase of draught. Her draught was 19.06, the Columbia showed increase both of overhang and draught. She was 41.34 feet longer over-all than on the waterline and her draught was 19.75. The Reliance breaks nil records as to overhang.