Sails are measured completely
in accordance with the
WS Equipment Rules of Sailing (ERS).
Sails shall be dry when measured, and on a
flat surface with just sufficient tension to remove any wrinkles across
the line of the measurement being taken. The following type of sails can
The maximum number of sails allowed on board while racing (not including
storm and heavy weather sails required by the WS Offshore Special
regulations) is defined by the ORC Rating Rule 206 as follows:
17.000 - 11.501
11.500 - 9.651
Headsails include those set on the forestay and headsails set
Spinnakers include symmetric and asymmetric.
Mainsail and Mizzen
The mainsail is measured with width at the
top (MHB) and four widths found on the leach
between head and clew: at 1/4 (MQW), 1/2 (MHW),
3/4 (MTW) and 7/8 (MUW) leech
heights. Points on the leech are found by folding the sail to
find equal distances between clew and head or between two
adjacent measurement points. The height of the mainsail luff (P)
and mainsail foot (E) are measured on the mast
and boom as part of the rig measurements.
The basic formula for mainsail area is
The mainsail measured area is calculated by
the simplified trapezoid formula above, dividing the luff in
amounts of 1/4, 1/2, 3/4 and 7/8. However, the mainsail rated
area is calculated by using the actual heights on the luff
from the tack point to the points where mainsail widths are
measured. The amount of roach will therefore proportionally
increase the rated area from the measured one by giving the
exact area and centre of effort height for square top and
other high roach main sails.
If there is a batten above the 7/8 (MUW) leech
point, then the top width (MHB) measurement is
increased taking in account effect of a batten positioned
this high on
Mizzen measurements are the same as for the mainsail, with all
corresponding measurements abbreviations having "Y" as a
Headsails shall have the
distance between half luff point and
half leech point of less than 75% or the foot
Headsails may be used on a furler system. In such a case, a rating credit will be given if
the furling system is used in association with one
Headsails may be set on the forestay or set flying, i.e.
with no sail edge attached to the rig. As a part of
measurement process, headsails shall be flagged when set
flying and/or having battens.
Inner jibs shall have their LPG of 110 % or less of J measurement and
shall be tacked inside another jib or spinnaker between the
forestay and the mast.
When a headsail is tacked inside spinnaker or inside another
headsail, if it is trimmed flat along the center line of the
boat, the clew shall not be aft of the clew of the foremost
headsail trimmed on the same way.
Headsail measurements are similar to those
of the mainsail, including the top width (HHB) as well as four widths
found on the leach between head and the clew: at 1/4 (HQW),
1/2 (HHW), 3/4 (HTW) and 7/8 (HUW)
leech heights. Points on the leech are found by folding the sail to find
equal distances between clew and head or between two adjacent
measurement points. Additional measurements for headsails are:
luff length (HLU) and luff perpendicular (HLP)
as the shortest distance from the clew point to the luff. Headsail area is
then calculated as follows:
When the leech has a clear hollow or the headsail is not the
largest in the sails inventory, measurements can be reduced to HLUand HLP only.
Spinnakers: Symmetric and Asymmetric
The half width of any
spinnaker shall be 75 % or more of the foot
The symmetric spinnaker shall be symmetric in
shape, material and cut, about a line joining the head to
the center of the foot. The symmetric spinnaker shall not
have adjustable leech lines.
Any spinnaker not qualifying as symmetric shall be
considered as asymmetric. Where the asymmetric
spinnaker is tacked on the centerline, tack pennants of any
length may be used.
Battens are not permitted on any spinnaker.
Spinnaker measurements include: leech length (SLU),
luff length (SLE), half width (SHW) as the distance between midpoints on the luff and leech and
the foot length (SFL). The asymmetric spinnaker luff ASL is then calculated as
the average of the luff length (SLU) and the leech length (SLE) making it possible to use the same formula for spinnaker
Symmetric spinnaker area
Asymmetric spinnaker area
Mizzen staysails shall be three-cornered. The
longest side edge shall be taken as a luff, the shortest edge shall
be taken as a foot, and third edge shall be taken as a leech. Mizzen
staysail measurements include: YSHF as the shortest
distance that can be measured from head to foot,
half width or distance between midpoints on the luff and leech,
and YSFL as the foot width.