Seaspray Catamaran Class Rules

 

1.      General

  •  The Seaspray is a 15’ catamaran

 2.   Hulls and Weight

  •  All hulls must comply to the original shape specifications of the designer or to the modified shapes affecting the bow, doghouse, and daggerboard slot produced by Glemore Sailboats Ltd.
  • Fairing and polishing are permitted.
  • Minimum weight is 180 lbs. fully rigged

 3.   Beam

  •  The maximum beam is 6’6” (six feet six inches)

 

4.   Bow Tube

  •  The bow tube shall be straight, round, 2” OD aluminum tube of not less than 0.050” nominal wall thickness.

 

5.   Mast Beam

  • The mast beam shall be straight, round, 4” OD aluminum tube of not less than 0.050” nominal wall thickness.
  • The mast beam may be reinforced as required to support the mast step and/or the trampoline.

 6.   Rear Main Beam

  •  The rear main beam shall be straight, round, 4” OD aluminum tube of not less than 0.050” nominal wall thickness.

 7.   Trampoline

  •  The trampoline deck shall substantially cover the area between the inner shear lines, the mast beam, and the rear main beam.
  • The trampoline shall lace to the rear beam leaving a maximum open distance of 5” between the forward edge of the beam and the lacing holes.
  • There shall be a trampoline deck support of a 2” OD aluminum tube between the mast beam and the rear main beam, on the center line of the boat.

 

8.   Daggerboards

  • There shall be two fitted, one in each hull.
  • The nominal maximum thickness shall be ¾” plus or minus ¼”.
  • Shape and size are optional.

9.   Rudders

  •  There shall be two fitted, one on each transom, mounted on the centerline with the leading edge of the rudder aft of the transom.
  • The thickness of the rudders shall be a nominal maximum thickness of ¾” plus or minus ¼”.
  • Shape and size are optional.

 10. Mast Step

  •  The mast step shall not extend more than 2” above the mast beam.

 11. Mast (revised 1995)

  •  Mast stiffening devices, spreaders, diamonds or jack stays are prohibited.

Where a sleeve or sock sail is used:

  •  The mast shall be a straight, 3” OD aluminum tube of not less than 0.050” nominal wall thickness.
  • The total length of the mast and fittings, excluding any wind indicator, shall not exceed 20’10” above the top of the mast beam.
  • The mast hounds and shroud attachments points shall be 13 feet plus or minus 2” from the lower extremity of the tube and within 1 ½” from the face of the tube.
  • The mast may be free to rotate.

 Where a halyard sail is used:

  •  The mast extrusion shall be a uniform untapered section.
  • The total length of the mast and fittings, excluding any wind indicator, shall not exceed 20’10” above the top of the mast beam.
  • The mast cross section shall be 3” in width and have a chord not exceeding 4”.
  • The mast hounds and shroud attachments points shall be 13 feet plus or minus 2” from the lower extremity of the tube and within 1 ½” from the face of the tube.
  • The mast may be free to rotate.

 12. Mast Bands 

  • The mast shall carry three bands of a color strongly contrasting with the color of the mast.
  • They shall be not less than 3/8” in width.
  • The bottom and top bands shall be spaced 18’7” apart from the upper part of the bottom band to the lower edge of the top band.
  • The upper band shall be located as close to the mast head as rigging will permit the mainsail to reach.
  • When racing, the head of the mainsail shall not come above the lower edge of the top band and the tack shall not come below the top edge of the lower band.
  • The lower edge of the middle band shall be not more than 13’2” above the lower extremity of the tube.
  • When racing, the head of the jib shall not come above the lower edge of the middle band.

 13. Boom 

  • The boom shall be a straight, round, 2” OD aluminum tube of not less than 0.050” nominal wall thickness.

14. Boom Band 

  • The boom shall carry a band of color strongly contrasting the boom.
  • The band shall be not less than 3/8” wide.
  • With the boom fitted on the goose neck and at right angles to the mast, the forward edge of the band shall be located 9’4” from the front center line of the mast.
  • When racing, the clew of the mainsail shall not go beyond the forward edge of the band.

 15. Standing Rigging

  • There shall be two shrouds and a bridle.
  • The forestay is optional.
  • All standing rigging shall be a minimum of 3/32” diameter stainless steel 1x19 wire.
  • The shrouds and forestay shall attach to the hounds at single point.
  • The shrouds shall attach to fittings in the hull at a point 24 ¾ “ plus or minus ¼”, aft and at right angles to the extended line of the aft edge of the mast beam.

 16. Running Rigging

  •  All running rigging shall be at the owner’s option.

 17. Foresail

  •  The foresail shall be constructed to fall within a triangle, the luff of which shall not exceed 12’6” in length, the leech not to exceed 11’3” in length, and the foot not to exceed 6’ in length.
  • A roach on the foot of the jib may extend beyond the triangle to a maximum of 2” at the foot’s center point.
  • The center point of the foot’s roach shall be measured from a straight line taken from the lowest point of the luff to the lowest point of the leech.
  • A positive or negative roach of 2” at the center point of the leech is permissible.
  • The center point of the leech roach shall be measured from a straight line taken from the lowest point of the clew to the highest point of the head.
  • There may be two battens in the leech, the upper not exceeding 9” in length and the lower not exceeding 12” in length.
  • The tack, clew and head of the jib must fall within the triangle.
  • The foresail weight shall not be less than 2 oz. per square yard.

 18. Mainsail

  •  The mainsail shall be loose footed and be attached to the mast by either a sock slid over the mast or by means of a luff groove extruded into or attached onto the mast.
  • Maximum inside width of a sock laid flat shall be 9”.
  • The mainsail is loosely based on a triangle truncated at the head.
  • Sides are specified, as are the cross measurements at the ¼, ½. ¾, and top batten heights.
  • Luff curve is allowed and unspecified.
  • Foot roach is allowed and specified.
  • The bolt rope is included in all measurements and must extend to the tack point.
  • The sock laid flat is considered part of the sail and is included in all measurements.
  • Just sufficient tension in the sail material is used to remove rolls and major wrinkles along the line being measured.
  • The sail has four corner points: tack, clew, fore-head, and aft-head.
  • The tack is the lowest and most forward point of the sail; the clew is the lowest of the most aft point(s) of the sail; the fore-head is the top most, forward point of the sail; the aft-head is the top most afterward point of the sail.
  • The four sides of the sail are: luff, leech, foot and head.
  • They are measured by taking the straight line distances between the corner points.

The maximum allowable measurements are:

 

      Side           Halyard           Sock 

      Luff           18’7”               18’7”

      Leech        19’8”               19’8”

      Foot           8’11 ½”           9’4”

      Head         5”                    9 ½”

 

  • The foot may have a roach which extends a maximum of 4” outside the line of the foot.
  • Cross measurements from luff to leech are specified and ¼, ½, and ¾ points.
  • These points are located by folding the sail twice along the leech using the aft corner points, and twice along the luff using the forward corner points – six points are thus located on the edge of the sail.

 The maximum allowable measurements are:

      Height       Halyard           Sock

      ¼               86 1/2"            91"

      ½               64 1/2"            69"

      ¾               40 ½”              45”

 

  • A maximum of five battens may be installed.
  • Maximum batten length is 27” except for the top batten of a sock sail which may be a maximum of 28 ½”.
  • The top inside edge of the upper batten pocket at the leech shall be at least 31” from the aft-heat point.
  • The bottom inside edge of the lowest batten pocket at the leech shall be at least 39 inches from the clew point.
  • The top batten point is defined as the point on the leech 31” from the aft-head point.
  • The top batten cross measurement is taken from the top batten point along a line to the luff, that line meeting the luff perpendicularly.
  • The maximum top batten cross measurement is 26 ½” for the halyard sail and 31” for the sock sail.
  •  The sail shall be constructed from sail cloth. Type and weight are optional.

 19.  Other Sails

  •  No other sails may be fitted.

 

20.  Miscellaneous 

  • No hiking aid may be used in Seaspray One Design competition other than toe straps.
  • Trapeze gear may be fitted for use in IYRU Class A competition.
  • Hydrofoils, ballast, spray deflectors, outriggers or any other device designed to alter the basic sailing characteristics of a Seaspray are expressly prohibited.
  • The total weight of clothing and equipment worn or carried by a competitor including buoyancy apparatus, shall not exceed 44 lbs or 20 kg when wet.
  • Fabric weight jackets, water pockets, compartments, or containers in or attached to clothing or equipment shall be permitted provided they can be drained or abandoned in less than ten seconds.