David the answer is more complex.
The AHPC website gives a ball park figure. And the spinnaker area is ruled by the F16 rules and not Taipan 4.9 rules as that class doesn't have a spinnaker.
The rules of interest to both jibs and spi are
Taipan rules :
http://www.ahpc.com.au/49rules.html18 The ISAF Guide to Sail Measurement 1997 - 2000 shall apply where no conflict with these rules arises. Battens shall be removed from the mainsail for measurement.
18 B. b. For a sloop, the rig shall consist of a mainsail and a headsail. For a cat-rig, the rig shall consist of a mainsail only.
18 c. i. The headsail shall be carried on the forestay.
The tack shall not extend below the intersection of the forestay with the forestay strop.
A device shall be used to prevent adjustment of the tack below this point.
18 c iii iii. The `Triangulation' method of measurement shall be used if the width of the sail at the head exceeds 50mm.
For the purpose of this rule the width at the head shall be measured at right angles to the luff through the highest point of the sail on the luff, to the line of the leech, extended if necessary.
iv. The length of the leech shall be not more than 5040mm.
v. The length of the luff shall be not more than 5100mm.
vi. The length of the foot shall be not more than 1730mm.
vii. The maximum foot round will be 50mm.
viii. At a point on the leech 200mm down from the head, the nearest point on the luff shall be not more than 100mm distant.
ix. At the half leech point the nearest point on the luff shall be not more than 790mm distant.
The half leech point shall be found by folding head to clew and smoothing the sail out flat.
x. Up to two battens are allowed in the leech only. Each batten shall be perpendicular to the leech, not be more than 200mm in length and not more than 20mm in width.
xi. The leech shall be in no place convex
xii. Headsail clew boards larger than 60mm in any dimension are prohibited.
Only one sheet attachment point is permitted.
With these rules implemented in a Goodall jib as measured by Texel system results in the following jib size :
4,17 sq. mtr. 4,72 mt. projected luff length (along mast)
With regard to spinnakers read the F16 rules on the subject :
http://www.geocities.com/f16hpclass/F16HP_class_rules.html1.10.1 The length of the gennaker boom shall not be more than 3,50 mtr.
1.14 Gennaker
1.14.1 The maximum distance measured from the top of the main beam to the heighest theoretical
point to which a gennaker sail can be hoisted is referred to as the Gennaker Hoist Height.
The Gennaker Hoist Height shall not be more than 7,50 mtr.
1.14.2 The distance to a mast gate may be used for the Gennaker Hoist Height measurement when no part of the gennaker can be hoisted past the distance measured.
1.14.3 The gennaker must satisfy the following two shape and size conditions :
SMG > 75% * SF
Gennaker sail area = SF * (SL1+SL2) / 4 + (SMG-SF/2) * (SL1+SL2) / 3 =< 17,50 sq. mtr.
Where :
* SMG is the width at mid-height, which shall be taken between the mid
point of the luff and the mid point of the leech.
* SF is the length of the foot of the sail measured around the edge of
the sail, between the lowest points of the luff and the leech ;
* SL1 is the length of the luff of the sail measured along the edge of
the sail, from the highest point of the sail, to the lowest point of the sail
on the luff ;
* SL2 is the length of the leech of the sail measured along the edge of
the sail, from the highest point of the sail, to the lowest point of the sail
on the leech.
Of course if you enter you Taipan as a F16 than you may alter your jib to an F16 compliant jib.
But I leave that for you to figure out with the supplied F16 rules as I have answered your question now.
Wouter