Mast Measurements

Mast
7.2.1 The mast may be stepped on the deck or into the hull. With the mast
spar perpendicular to the base line, the after side at deck level shall not
be less than 3048mm and not more than 3202mm forward of Station
11. The mast spar may be fixed or rotating. No dimension of the mast
spar cross section shall exceed 102mm.
7.2.2 A maximum of 30mm mast spar curvature is permitted.
7.2.3 Limit marks not less than 10mm in width shall be placed round the
mast at the following three positions measured with the mast standing
perpendicular to the baseline.
• Deck limit mark: upper edge level with the top of the deck. –
tolerance 1 mm (mast datum point).
• Lower limit mark: upper edge not less than 381mm above the
mast datum point (lower point).
• Upper limit mark: lower edge not more than 6858mm above the
mast datum point (upper point).
• The top point of the mast spar shall be not more than 7011mm
above the mast datum point.
7.2.4 The spinnaker hoist height shall be not more than 5955 mm nor less
than 5054 mm. No rigidly fixed point for attachment of the block,
sheave or fairlead shall be more than 35 mm from the surface of the
mast spar.
7.2.5 The highest point of entry onto the block, sheave or fairlead for the
headsail halyard shall not be more than 4750mm and not less than
4648mm above the mast datum point. A prolongation of the luff of the
headsail when set shall cut the fore-side of the mast between these
limits.
7.2.6 These measurements apply to masts whether fitted with mastjacks or
otherwise. At all times when sailing, an extension of the upper surface
of the deck shall intersect the mast at the upper edge of the deck limit
mark.