here ya go!
(3-B-1) *Hull*
Only fiber composite construction molded V bottom monohulls are permitted. The running surface maybe straightened but not modified and a transom turn fin is optional.

(3-B-2) *Minimum (and maximum) Dimensions*
(Class = Weight,Length,Width,depth)
GT3O = boat & driver 250 kg (550 Ibs), 3.50 m (11' 5")
T 750 = boat & driver 270 kg (594 lbs), 4.00 m (13' 1"), 1.40 m (4' 7"), 0.40 m (1' 3")
T 850 = boat & driver 330 kg (726 lbs), 4.00 m (13' 1"), 1.40 m (4' 7"), 0.40 m (1' 3")
The maximum length for T750 is 4.25 m [13' 11"]
The maximum length for T850 is 4.60 m [15' 1"]
The maximum allowed ballast weight is 10 % of the specified minimum weight for each individual class. The ballast must be attached and on the inside of the hull.
The minimum weight mentioned here above is the weight of a complete rig weighed directly after the race including driver, personal safety equipment, and residual fuel but without residual water.
Measurements are taken while the boat is ashore. The length must be measured as the overall length of the hull between perpendiculars at the foremost and aft most rigid part of the hull. The width of the boat is measured at the widest part of the hull.

The minimum T boat weights are difficult to be under. This almost eliminates the need for the inspector[s] to weigh boats at races. We weigh them normally at the spring T party. In weighing boats so far we have only weighed one boat that was close to the minimum weight. Example most T850's are over 765 lbs. So don't worry about being on weight. If the boat is built to light it will break up in the rough water.