Section E — Radio Sailing Racing Rules

Rule G1 applies to every boat of a class administered or recognized by World Sailing or by the International Radio Sailing Association (IRSA).

• (a) Unless her class rules state otherwise, a boat of a World Sailing or IRSA Class shall comply with rule G1 and shall carry:
  (1) on her mainsail, her class insignia and national letters (if required).
  (2) on all sails, her sail number.
• (b) Sails shall comply with rule E8 at world and continental championships. At other events, they shall comply with these rules or the rules applicable at the time of their initial certification.

At IRSA world and continental championships and events described as international events in their notices of race, a boat shall carry national letters from the table in Appendix G, rule G1 denoting:

• (a) when entered under rule 75(a), the boat’s national authority, or
• (b) the competitor’s country of residence, or
• (c) the national authority of the owner or competitor.

Note: An up-to-date version of the National Sail Letters table is available on the World Sailing website.

• (a) The sail number shall be the last two digits of:
  (1) the hull registration number, or
  (2) the competitor’s or the owner’s personal number allotted by the relevant issuing authority.
• (b) A single digit hull number or personal number shall be preceded by a zero.
• (c) If there is conflict between sail numbers, or if a sail number may be misread, the race committee shall require that the sail numbers of one or more boats be changed to numeric alternatives.

• (a) National letters and sail numbers shall be in capital letters and Arabic numerals, clearly legible and of the same colour. The colour shall contrast with the colour of the body of the sail. Commercially available typefaces giving the same or better legibility than Helvetica are acceptable. Digital fonts are not acceptable.
• (b) The height and spacing of letters and numbers shall be as follows:

• (a) Class insignia, sail numbers and national letters shall be positioned
  (1) on both sides of the sail;
  (2) with those on the starboard side uppermost;
  (3) approximately horizontally;
  (4) with space for a prefix ‘1’ in front of the sail number; and
  (5) with no less than 40 mm vertical spacing between lines of numbers and letters on opposite sides of the sail.
  However, symmetrical or reversed class insignia may be positioned back to back.
• (b) Symmetrical or reversed class insignia shall be on the mainsail, above a line perpendicular to the luff through the three-quarter leech point, and may be positioned back-to-back. Otherwise, the vertical spacing shall be no less than 20 mm.
• (c) On a mainsail, sail numbers shall be positioned
  (1) below class insignia;
  (2) above the line perpendicular to the luff through the quarter leech point;
  (3) above national letters.

Where the size of the sail prevents compliance with rule G1.4 or G1.5, they shall be amended as follows and in the following order of precedence:

• (a) sail numbers may extend below the specified line;
• (b) vertical spacing may be reduced to no less than 20 mm:
  (1) first between sail numbers and national letters, and
  (2) then between national letters;
• (c) height of national letters may be reduced to no less than 40 mm or shall be omitted;
• (d) vertical spacing of sail numbers may be reduced to no less than 20 mm;
• (e) height of sail numbers shall be reduced to less than 90 mm, but no less than 80 mm, or shall be omitted except on the largest sail.

Other boats shall comply with rule E8 unless the rules regarding the allotment, carrying and size of insignia, letters and numbers are changed by their national authority or class association. Such changed rules shall, when practicable, conform to the above requirements.